Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Rayed Bean, Sheepnose, Snuffbox, and Spectaclecase Mussels

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R3-ES-2024-0144; FXES1111090FEDR-267-FF09E21000]

RIN 1018-BH73

Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Rayed Bean, Sheepnose, Snuffbox, and Spectaclecase Mussels

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Final rule.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), are designating critical habitat for the rayed bean (

Villosa fabalis

), sheepnose (

Plethobasus cyphyus

), snuffbox (

Epioblasma triquetra

), and spectaclecase (

Cumberlandia monodonta

), all species of freshwater mussel, under the Endangered Species Act of 1973, as amended (Act). Specifically, we designate approximately 599 river miles (rmi) (964 river kilometers (rkm)) in 15 units as critical habitat for rayed bean; approximately 801 rmi (1,289 rkm) in 11 units as critical habitat for sheepnose; approximately 2,425 rmi (3,902 rkm) in 38 units as critical habitat for snuffbox; and approximately 1,140 rmi (1,835 rkm) in 12 units as critical habitat for spectaclecase. Portions of these designations overlap among the four species; in total, approximately 3,814 unique rmi (6,138 rkm) of critical habitat within 76 units across 17 States (Alabama, Arkansas, Illinois, Indiana, Iowa, Kentucky, Michigan, Minnesota, Mississippi, Missouri, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin) fall within the boundaries of the critical habitat designations.

DATES:

This rule is effective May 27, 2026.

ADDRESSES:

This final rule is available on the internet at

https://www.regulations.gov.

Comments and materials we received are available for public inspection at

https://www.regulations.gov at

Docket No. FWS-R3-ES-2024-0144.

Availability of supporting materials:

Supporting materials we used in preparing this rule, such as the species status assessment reports and recovery plan, are available at

https://www.regulations.gov

at Docket No. FWS-R3-ES-2024-0144, or at the Service's website on each individual species' page (rayed bean:

https://www.fws.gov/species/rayed-bean-villosa-fabalis;

sheepnose:

https://www.fws.gov/species/sheepnose-plethobasus-cyphyus;

snuffbox:

https://www.fws.gov/species/snuffbox-epioblasma-triquetra;

spectaclecase:

https://www.fws.gov/species/spectaclecase-cumberlandia-monodonta

). The coordinates or plot points or both from which the critical habitat maps are generated are included in the decision file for this critical habitat designation and are available at

https://www.regulations.gov

at Docket No. FWS-R3-ES-2024-0144.

FOR FURTHER INFORMATION CONTACT:

Rayed bean and snuffbox: Erin Knoll, Field Supervisor, U.S. Fish and Wildlife Service, Ohio Ecological Services Field Office; telephone 614-416-8993;

erin_knoll@fws.gov;

sheepnose: Kraig McPeek, Field Supervisor, U.S. Fish and Wildlife Service, Illinois-Iowa Ecological Services Field Office; telephone 309-757-5800;

kraig_mcpeek@fws.gov;

spectaclecase: Rob Tawes, Field Supervisor, U.S. Fish and Wildlife Service, Minnesota-Wisconsin Ecological Services Field Office; telephone 612-240-6343;

robert_tawes@fws.gov.

Individuals in the United States who are deaf, deafblind, hard of hearing, or have a speech disability may dial 711 (TTY, TDD, or TeleBraille) to access telecommunications relay services. Individuals outside the United States should use the relay services offered within their country to make international calls to the point-of-contact in the United States.

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish a rule.

Under the Act (16 U.S.C. 1531

et seq.

), when we determine that any species is an endangered or threatened species, we are required to designate critical habitat to the maximum extent prudent and determinable. We are finalizing a designation of critical habitat for four species of freshwater mussels. Designation of critical habitat can be completed only by issuing a rule through the Administrative Procedure Act rulemaking process (5 U.S.C. 551

et seq.

).

What this document does.

This rule will designate critical habitat for the rayed bean, sheepnose, snuffbox, and spectaclecase mussels; these four freshwater mussel species have been listed as endangered species under the Act since 2012 (See 77 FR 8632, February 14, 2012, and 77 FR 14914, March 13, 2012).

The basis for our action.

Under section 4(a)(3) of the Act, if we determine a species is an endangered or threatened species, the Secretary of the Interior (Secretary) must designate critical habitat to the maximum extent prudent and determinable. Section 3(5)(A) of the Act defines critical habitat as (i) the specific areas within the geographical area occupied by the species, at the time it is listed, on which are found those physical or biological features (I) essential to the conservation of the species and (II) which may require special management considerations or protections; and (ii) specific areas outside the geographical area occupied by the species at the time it is listed, upon a determination by the Secretary that such areas are essential for the conservation of the species. Section 4(b)(2) of the Act states that the Secretary must make the designation on the basis of the best scientific data available and after taking into consideration the economic impact, the impact on national security, and any other relevant impacts of specifying any particular area as critical habitat.

Previous Federal Actions

Please refer to the December 13, 2024, proposed critical habitat rule (89 FR 101100) for a detailed description of previous Federal actions concerning the rayed bean, sheepnose, snuffbox, and spectaclecase mussels.

Peer Review

A species status assessment (SSA) team prepared an SSA report for each of the four mussel species. The SSA team was composed of Service biologists, in consultation with other species experts. The SSA reports represent a compilation of the best scientific and commercial data available concerning the status of the species, including the impacts of past, present, and future factors (both negative and beneficial) affecting the species.

In accordance with our joint policy on peer review published in the

Federal Register

on July 1, 1994 (59 FR 34270), and our August 22, 2016, memorandum updating and clarifying the role of peer review in listing and recovery actions under the Act (

https://www.fws.gov/sites/default/files/documents/peer-review-policy-directors-memo-2016-08-22.pdf

), we solicited independent scientific review of the information contained in the SSA reports for the rayed bean (Service 2022a, entire), sheepnose (Service 2022b, entire), snuffbox (Service 2022c, entire), and spectaclecase (Service 2022d, entire). As discussed in the proposed rule, we sent the SSA reports to 10 independent peer

reviewers and received 9 responses. The peer reviews can be found at

https://www.regulations.gov

at Docket No. FWS-R3-ES-2024-0144. In preparing the proposed rule, we incorporated the results of these reviews, as appropriate, into the SSA report, which was the foundation for the proposed rule and this final rule. A summary of the peer review comments and our responses can be found in the December 13, 2024, proposed rule (89 FR 101100).

Summary of Changes From the Proposed Rule

After considering the comments we received during the public comment period for our December 13, 2024, proposed rule to designate critical habitat for the rayed bean, sheepnose, snuffbox, and spectaclecase mussels (89 FR 101100) and relevant information that became available since the proposed rule published, we made changes to this final critical habitat rule. No changes were required for our economic analysis after considering public comments; however, we updated the screening memo to reflect relevant changes necessary for addressing recent Executive Orders as well as the updated unit descriptions, described below. These minor updates did not result in any changes to the overall findings of the screening memo; thus, we consider the July 3, 2025, economic analysis as final (Industrial Economics, Incorporated (IEc) 2025, entire). We made many small, nonsubstantive changes throughout this document that do not affect the designations (

e.g.,

making minor edits for clarity throughout the rule, updating references to enacted and rescinded Executive Orders and Department of the Interior Secretary's Orders). Below is a summary of changes made in this final rule.

(1) We made minor edits to the

Summary of Essential Physical or Biological Features

to clarify which physical or biological features are essential to the conservation of each species in an effort to resolve confusion expressed during the public comment period. Specifically, we added explicit statements about which substrate types are considered suitable habitat for each species using information that was presented in table 1 of the Physical or Biological Features Essential to the Conservation of the Species section of the proposed critical habitat rule (89 FR 101100 at 101105; December 13, 2024).

(2) In an effort to resolve confusion expressed during the public comment period, we made minor edits to the Criteria Used to Identify Critical Habitat section to clarify the methodology used to identify areas as critical habitat for each species. During the public comment period, multiple commenters were confused about the application of “risk” terminology in the Criteria Used to Identify Critical Habitat compared to the “risk” evaluation described in the SSA report. In the proposed rule, the term “risk” was used in a general sense of the term to describe what was meant by a “high-condition” or “moderate-condition” population, in plain language, rather than indicate identified risks acting on a population as described in the SSA report. This unintentional conflation of terms resulted in some confusion around how we delineated critical habitat units. As such, in this final rule, we removed the term “risk” from our methodology to reduce confusion and better convey our approach for defining areas as critical habitat.

(3) We extended the critical habitat designation for rayed bean (RABE) 9: Allegheny River to include additional areas upstream of the proposed designation in areas that are considered to be occupied by the species and that contain the physical or biological features based on information we received during the comment period. Specifically, we extended the critical habitat designation in the Allegheny River upstream from its confluence with Oswayo Creek near Portville (Cattaraugus County, New York) to the Allegheny River's confluence with Sartwell Creek near Burtville (McKean County, Pennsylvania). We also extended the critical habitat designation in Oswayo Creek upstream from the New York/Pennsylvania State Line in Allegany County, New York, and McKean County, Pennsylvania, upstream to Oswayo Creek's confluence with Honeoye Creek in Potter County, Pennsylvania. Finally, we added Honeoye Creek from its confluence with Oswayo Creek upstream to the New York/Pennsylvania State Line in Allegany County, New York, and Potter County, Pennsylvania. In total, these revisions to RABE 9 result in an increase of approximately 49 river miles (rmi) (79 river kilometers (rkm)) of critical habitat from the areas we proposed.

(4) We extended the critical habitat designation for RABE 10: Middle Allegheny River to include additional stream segments upstream and downstream of the proposed designation in areas that are considered to be occupied by the species and that contain the physical or biological features, based on information we received during the comment period. Specifically, we added Oil Creek from the Oil Creek State Park Ice Control Dam in Venango County, Pennsylvania, downstream to Oil Creek's confluences with the Allegheny River in Oil City (Venango County, Pennsylvania). Additionally, we extended critical habitat downstream in the Allegheny River from its previous terminus at Lock and Dam Number 5 in Armstrong County, Pennsylvania, downstream to the Allegheny River's mouth at the Kiskiminetas River in Armstrong County, Pennsylvania. These revisions to RABE 10 result in an increase of approximately 8 rmi (13 rkm) of critical habitat from the areas we proposed.

(5) We updated the unit description for RABE 15: Tippecanoe River within the preamble and the regulatory text and updated the map within the regulatory text. Specifically, we divided RABE 15: Tippecanoe River into two subunits within a larger unit instead of describing it all as a single unit; however, the overall designation did not change. As written in the proposed rule, the critical habitat designation excluded Lakes Shafer and Freeman and the stretch of the Tippecanoe River between the two lakes, which resulted in two disjunct portions of critical habitat on the Tippecanoe River—now referred to as subunits. Although the unit description did not include the two lakes and the stretch of the Tippecanoe River as critical habitat (

i.e.,

this area was excluded by text), this segment was inadvertently included within the regulatory maps of the proposed rule (89 FR 101100 at 101148-101149). We updated the map in this final rule to show only the subunits as critical habitat within RABE 15: Tippecanoe River.

(6) We updated the unit description for snuffbox (SNBO) 2: Embarrass River within the preamble and the regulatory text by dividing the unit into two subunits instead of describing it all as a single unit; however, the overall designation did not change. As written in the proposed rule, the unit description was not clear that there was a break within the critical habitat unit that corresponds to Caroline Pond 247 in Shawano County, Wisconsin. As such, we updated the unit description so that subunit SNBO 2a contains the South Fork Embarrass River portion of the unit and subunit SNBO 2b contains the Embarrass River and North Fork Embarrass River portions of the unit. We updated the unit map within the regulatory text to show the subunit designations.

(7) We updated the unit description for SNBO 9: French Creek within the preamble and the regulatory text and updated the unit map within the regulatory text. Specifically, we divided

SNBO 9: French Creek into two subunits within a larger unit instead of describing it all as a single unit; however, the overall designation did not change. As written in the proposed rule, the unit description was not clear that there was a break in the area designated as critical habitat within the mainstem of the French Creek that corresponds with areas that are not considered to be occupied by the species and that do not contain the physical or biological features essential to the conservation of the species as a result of impounded habitat for Union City Lake. As such, we updated the unit description within this final rule to describe two subunits. SNBO 9 subunit A contains the areas designated as critical habitat upstream of Union City Lake, and SNBO 9 subunit B contains the areas downstream of the Union City Dam that creates Union City Lake. With regard to the unit map, despite the West Branch French Creek being included in the proposed unit descriptions, this segment was inadvertently omitted from the map within the proposed rule's regulatory text (89 FR 101100 at 101169; December 13, 2024). We updated the unit map to show the area designated as critical habitat within the West Branch French Creek.

(8) We updated the critical habitat designation for SNBO 13: Little Kanawha River by removing a portion of the Little Kanawha River from its confluence with the Hughes River downstream to the Little Kanawha River's confluence with the Ohio River in Parkersburg (Wood County, West Virginia). Based on information we received during the comment period, this stretch of the Little Kanawha River is not considered to be either historically or currently occupied habitat for the snuffbox as it does not contain the physical or biological features essential to the conservation of the species and is heavily impacted by siltation. Thus, this area does not meet our definition of critical habitat. The updated SNBO 13 designation now terminates at the confluence of the Little Kanawha River and the Hughes River near Greencastle (Wirt County, West Virginia), but it still includes the Hughes River portion of the designation. This revision to SNBO 13 results in a decrease of approximately 18 rmi (29 rkm) from the areas we proposed.

(9) We updated the critical habitat designation for SNBO 14: Kanawha River by removing the upstream portion of the Elk River between Sutton Dam in Braxton and Webster Counties, West Virginia, and the Pisgah Ridge Road/Elk Street crossing near the town of Clay (Clay County, West Virginia). Based on information we received in the comment period, this portion of the Elk River is not considered to be historically or currently occupied by the species. Despite apparent suitability and the lack of significant movement barriers, the lack of known records within this stretch of river indicates that some unknown environmental factors are limiting the ability of this river segment to support the species. As such, this area does not meet our definition of critical habitat for snuffbox. The updated SNBO 14 now begins at the Pisgah Ridge Road/Elk Street crossing near Clay (Clay County, West Virginia), and extends downstream in the area we proposed. This revision to SNBO 14: Kanawha River results in a decrease of approximately 49 rmi (79 rkm) from the areas we proposed.

(10) We extended the critical habitat designation for SNBO 16: Little Darby Creek further downstream in occupied areas where the physical or biological features are present, based on information we received during the comment period. The proposed unit stopped at the U.S. Highway 40 Bridge crossing near the village of West Jefferson (Madison County, Ohio); however, the unit now extends downstream to the Little Darby Creek's confluence with the Big Darby Creek (Franklin County, Ohio). This revision to SNBO 16: Little Darby Creek results in an increase of approximately 7 rmi (11 rkm) from the areas we proposed.

(11) We extended the critical habitat designation for SNBO 17: Big Darby Creek further downstream in occupied areas where the physical or biological features are present, based on information we received during the comment period. The proposed unit stopped at the State Highway 665 Bridge west of the unincorporated community of Darbydale (Franklin County, Ohio); however, it now extends downstream to the Big Darby Creek's confluence with the Scioto River near the city of Circleville (Pickaway County, Ohio). This revision of SNBO 17: Big Darby Creek results in an increase of approximately 31 rmi (50 rkm) from the areas we proposed.

(12) We updated the unit description for SNBO 27: Tippecanoe River within the preamble and the regulatory text and updated the map within the regulatory text. Specifically, we divided SNBO 27: Tippecanoe River into two subunits within a larger unit instead of describing it all as a single unit; however, the overall designation did not change. As written in the proposed rule, the critical habitat designation excluded Lakes Shafer and Freeman and the stretch of the Tippecanoe River between the two lakes, which resulted in two disjunct portions of critical habitat on the Tippecanoe River—now referred to as subunits. Although the unit description did not include the two lakes and the stretch of the Tippecanoe River as critical habitat (

i.e.,

this area was excluded by text), this segment was inadvertently included within the regulatory maps of the proposed rule (89 FR 101100 at 101184-101185). We updated the map in this final rule to show only the subunits as critical habitat within SNBO 27: Tippecanoe River.

(13) We made minor updates to all unit descriptions to reflect changes in the status (

i.e.,

proposed or final) of critical habitat designations to reflect the best scientific data available at the time of publication for this final rule.

(14) We updated the spectaclecase (SPCA) 9: Clinch River Unit to resolve a mapping error that overestimated the actual river mileage of the designation. This update resulted in an approximately 3 river mile (5 river kilometer) decrease in the total critical habitat for that unit and the overall total designation for spectaclecase. Given the overlap of this unit with the other designations, the total amount of unique river miles in the designation across the four species remains unchanged.

(15) We updated each species' critical habitat unit description summary tables (table 2 through table 5, below) to include a summary of approximate river mileage by land ownership type (

i.e.,

Federal, State, Local). Within the proposed rules, these tables only reported river mileages by Public and Private land ownership types.

Summary of Comments and Recommendations

In the proposed rule published on December 13, 2024 (89 FR 101100), we requested that all interested parties submit written comments on the proposal by February 11, 2025. We also contacted appropriate Federal and State agencies, Tribal entities, scientific experts and organizations, and other interested parties and invited them to comment on the proposal. Newspaper notices inviting general public comment were published in USA Today on December 20, 2024. We did not receive any requests for a public hearing. All substantive information received during the comment period has either been incorporated directly into this final rule or is addressed below.

Federal Agency Comments

(1) Comment:

One Federal Agency requested that we exclude critical habitat under section 4(b)(2) of the Act.

Specifically, they requested that portions of Unit SPCA 2 (in the Mississippi River) that are “not suitable habitat” for the spectaclecase mussel be excluded from the critical habitat designation; the agency commented that excluding areas of “not suitable habitat” would reduce the burden placed on project proponents in evaluating areas which are known to not provide any additional protection for the species.

Our response:

The Act requires the Service to designate critical habitat for listed species to the maximum extent prudent and determinable and does not restrict such designation to particular land ownership. Rather, areas that meet the definition of critical habitat, as determined on the basis of the best scientific data available, are proposed for designation. However, section 4(b)(2) of the Act further provides that the Secretary, in designating critical habitat and making revisions, shall take into consideration the economic impact, the impact on national security, and any other relevant impact of specifying any particular area as critical habitat. According to our Policy Regarding Implementation of Section 4(b)(2) of the Endangered Species Act (81 FR 7226; February 11, 2016), we consider six elements when considering whether or not to exclude an area from critical habitat: (1) partnerships and conservation plans; (2) conservation plans permitted under section 10 of the Act; (3) national security and homeland security impacts; (4) Tribal lands; (5) Federal lands; and (6) economic impacts. The Secretary may then choose to exercise their discretion to exclude any area from critical habitat if they determine that the benefit of exclusion outweighs the benefits of specifying such areas as part of the critical habitat, unless that exclusion would result in the extinction of the species. Under the Services' Policy Regarding Implementation of Section 4(b)(2) of the Endangered Species Act (81 FR 7226; February 11, 2016), a proponent of such an exclusion must provide a reasoned rationale for such exclusion, including measures undertaken to conserve species and habitat on the land at issue (such that the benefit of inclusion is reduced).

Regarding the request for the Secretary to use their discretion to exclude areas of “not suitable habitat” of Unit SPCA 2 in the Mississippi River from the critical habitat designation for spectaclecase this unit is occupied by the species and contains the physical or biological features essential to the conservation of the species. Moreover, habitat for and evidence of the species has been found within the navigation channel and throughout the large pools within the unit. The commenter did not provide any information to support their request to remove areas because they are “not suitable habitat.” These areas are occupied by the species and any discretionary Federal action would need to comply with the provisions of section 7(a)(2) as required under the Act. Accordingly, we did not exclude areas within Unit SPCA 2 from the critical habitat designation.

Comments From States

(2) Comment:

For sheepnose, the West Virginia Division of Natural Resources and multiple public commenters requested additional critical habitat across the species' range. They provided information in support of adding entire units, extending critical habitat upstream or downstream of proposed units, or both. Specifically, we received a request from the West Virginia Division of Natural Resources to consider adding critical habitat within the Ohio River along the border of West Virginia and Ohio within populations identified in the SSA report (

i.e.,

Raccoon-Symmes, Upper Ohio-Shade, Little Muskingum-Middle Island) and the Kanawha River in West Virginia from Kanawha Falls downstream to the Town of Deepwater. Additionally, we received requests from public commenters to consider adding critical habitat within the Ohio River along the border of Illinois, Indiana, Kentucky, Ohio, and West Virginia within populations identified in the SSA report (

i.e.,

Lower Ohio, Lower Ohio-Little Pigeon, Silver-Little Kentucky, Ohio Brush-Whiteoak, Little Scioto-Tygarts, Raccoon-Symmes, Upper Ohio-Shade, Little Muskingum-Middle Island); and the Mississippi River from its confluence with the Chippewa River downstream through Pool 5. As part of these requests, commenters noted a lack of sampling effort in these larger waterbodies (

e.g.,

the Ohio River) and the importance of maintaining connectivity of mussels and their fish hosts between disjunct tributaries through the mainstems of these larger, navigable waterbodies.

Our response:

Critical habitat is one of the many tools that supports the continued conservation of imperiled species by guiding cooperation within the Federal government. While the intent of designating critical habitat is to identify specific areas that are indispensable to the conservation of a species, it is important to note that the lack of critical habitat does not preclude coordination and implementation of recovery actions. Our decisions on whether or not to adjust critical habitat, summarized below, are supported by the best available science to identify areas that contain the physical or biological features essential to the conservation of the species, as outlined in our methodology. Additionally, we recognize that the implementation of multiple tools across additional populations, as outlined in the recovery plan for these four species, will be crucial to achieve species' recovery. We assessed all literature and data provided during the public comment period. In most instances, these data were redundant with information that was considered as part of the SSA report (Service 2022b, entire), the recovery plan for these four species of freshwater mussels (Service 2024, entire), or both, which formed the basis of our critical habitat designation. Several comments, however, pertained to decisions associated with the cumulative population size and reproduction and recruitment metrics outlined in Appendix C of the sheepnose's SSA report (Service 2022b, pp. C-1-C-4) and a few of these comments provided new data that we incorporated into our considerations for this final rule.

We identified critical habitat for sheepnose based on the physical or biological features essential to the conservation of sheepnose and considering the data provided for and population conditions estimated within the sheepnose SSA (Service 2022b, entire), the four mussel recovery plan (Service 2024, entire), and the public comment period for the proposed rule (89 FR 101100; December 13, 2024). All population conditions were estimated in accordance with the best scientific data available, and expert opinions were integrated under certain conditions, as discussed in Appendix C of the SSA report (Service 2022b, pp. C-1-C-4). Condition category assignments were otherwise data-driven for a comparative approach across populations, resulting in instances where text descriptions capturing expert opinions within the SSA report may not exactly align with the assessed Current Demographic Condition category or subcategories for a given population.

After assessing all additional data received during the public comment period in conjunction with the data used to develop the proposed designation of critical habitat (89 FR 101100; December 13, 2024), we determined that in all instances—except for one—the data were duplicative of information that we already considered or did not result in a change in the current demographic condition of the population. As such, these data do not result in changes that meet our criteria

for considering portions of the Ohio River (Lower Ohio, Lower Ohio-Little Pigeon, Silver-Little Kentucky, Ohio Brush-Whiteoak, Little Scioto-Tygarts, Upper Ohio-Shade, Little Muskingum-Middle Island), upper Mississippi River from its confluence with the Chippewa River downstream through Pool 5 (Buffalo-Whitewater), or the Kanawha River in West Virginia from Kanawha Falls downstream to the Town of Deepwater (Upper Kanawha) as critical habitat for the sheepnose.

For the Raccoon-Symmes population, however, we received data that resulted in the current demographic condition for this population changing from “low” to “moderate” due to the updated information documenting the collection of a juvenile individual in 2020. Although the demographic condition of this population improved, we have determined that this population does not meet our criteria to consider the Raccoon-Symmes portion of the Ohio River as critical habitat for sheepnose. While the “moderate” demographic condition of this population warrants that we consider this population on a case-by-case basis under the second criteria of our methodology—outlined in the

Methodology Used for Selection of Critical Habitat Units

section, below—the lack of connectivity of this population to other areas of high or moderate demographic condition or overlap with other areas of existing critical habitat precludes its inclusion as critical habitat.

We agree with commenters that portions of the Ohio River—and other large rivers—remain largely under-sampled, and we recognize that systemic survey efforts range-wide are generally lacking, both of which result in unknowns associated with the current status of many populations. In development of the SSA and recovery plan for these four mussel species, we relied on data provided by State natural resource agencies and Service field offices to inform the metrics used to assess the current demographic conditions of each population. Additionally, we requested that State agency partners provide a technical review of the defined current demographic condition and population description, presented in both the SSA report and the recovery plan, for the respective populations occurring within their areas of management to ensure that available data reflected observed conditions.

Finally, while we agree that mainstem reaches are important for allowing movement of host fish and genes between populations in disjunct tributaries to maintain demographic and genetic health (

i.e.,

genetic variability and adaptive capacity) of populations, these mainstem areas do not meet our criteria for designation of critical habitat. We included mainstem reaches (

e.g.,

the Lower Tennessee River) where appropriate, regardless of navigability status, where they met the definition of critical habitat. In the case of the Ohio River and the upper Mississippi River units that were requested for addition, available data did not support the classification of these areas as having comparatively large populations with evidence of sizeable levels of regularly occurring reproduction over time with high recovery potential. These areas do not overlap with existing critical habitat or occupied areas for other listed species, and these areas do not contain unique habitats that would contribute meaningfully to adaptive capacity of the species. While these areas are important for the sheepnose, they do not meet our criteria for inclusion as critical habitat within this final designation. Although they may be important for the recovery of sheepnose (along with other areas of suitable habitat), they do not meet the definition of critical habitat.

The occupied areas that meet the definition of critical habitat for sheepnose contain the physical or biological features essential to the conservation of the species and meet the Criteria Used to Identify Critical Habitat, described below. This subset of areas is also supported by the sheepnose's recovery plan, which identifies areas that support the healthiest remaining populations, have high recovery potential, and support genetically distinct populations that are important for the conservation and recovery of sheepnose.

Public Comments

(3) Comment:

For rayed bean, some commenters requested that we expand areas of critical habitat within Little Darby Creek and Big Darby Creek in Ohio, stating that despite the lack of recent rayed bean records, the presence of other mussel species within these waterbodies suggests that inclusion of these areas should be considered.

Our response:

As described in our response to comment (2), above, we used the rayed bean SSA report (Service 2022a, entire) and the recovery plan for these four species of freshwater mussels (Service 2024, entire), and we based the critical habitat designations on the best scientific information available. We assessed all data provided during the public comment period. Although the commenters provided information that documented the presence of the rayed bean within these river segments, the records provided were from the historical period (

i.e.,

prior to the year 2000), and thus the areas requested for addition are not considered to be occupied at the time of listing.

Although these areas may be important for the rayed bean (in addition to other areas of potentially suitable habitat), the occupied areas that meet the definition of critical habitat for rayed bean contain the physical or biological features essential to the conservation of the species and meet the Criteria Used to Identify Critical Habitat, described below. This subset of occupied areas supports the rayed bean's recovery plan, which identifies areas that support the healthiest remaining populations, have high recovery potential, and support genetically distinct populations that are important for the conservation and recovery of species. We are not designating any areas outside the geographical area occupied by the species because we have not identified any unoccupied areas that meet the definition of critical habitat, and we have determined that occupied areas are sufficient to conserve the rayed bean. As such, we are not expanding areas of critical habitat within Little Darby and Big Darby Creeks because they do not meet our criteria for inclusion as critical habitat.

(4) Comment:

For snuffbox, multiple public commenters requested additions or expansions of the critical habitat designation across the species' range. Specifically, we received requests for adding critical habitat within the Mississippi River below Lock and Dam 1 and expanding critical habitat within the Middle Fork Kentucky River and Red Bird River in Kentucky.

Our response:

As described in our response to comment (2), above, we used the snuffbox SSA report (Service 2022c, entire) and the recovery plan for these four species of freshwater mussels (Service 2024, entire). We assessed all data provided during the public comment period. Although these data provided some additional records in the Middle Kentucky River and the Red Bird River, these observations were either redundant with the records considered as part of the SSA report, recovery plan, or were historical observations for the species. In the instance of the upper Mississippi River, while we agree that the snuffbox is present within this segment, its demographic condition is considered to be “low” with a “high” risk based on the SSA report (Service 2022c, pp. 28-30), and the provided information did not change that categorization. Although these areas may be important for the

snuffbox (in addition to other areas of potentially suitable habitat), the occupied areas that meet the definition of critical habitat for snuffbox contain the physical or biological features essential to the conservation of the species and meet the Criteria Used to Identify Critical Habitat, described below. This subset of occupied areas supports the snuffbox's recovery plan, which identifies areas that support the healthiest remaining populations, have high recovery potential, and support genetically distinct populations that are important for the conservation and recovery of species.

We are not designating any areas outside the geographical area occupied by the species because we have not identified any unoccupied areas that meet the definition of critical habitat, and we have determined that occupied areas are sufficient to conserve the snuffbox. Within the species' recovery plan, we outline that recovery can be achieved by protecting and maintaining or enhancing existing occupied areas, with no need to create or establish new habitat areas or populations for snuffbox. As such, we determined that the areas that are suggested for inclusion as critical habitat are not known to be occupied by the species or do not meet our criteria for inclusion as critical habitat and thus were not identified as such.

(5) Comment:

Multiple commenters requested that the Service consider unoccupied areas of critical habitat for each species, suggesting that the proposed critical habitat designation was not sufficient to protect the species.

Our response:

We did not propose to designate any areas outside of the geographical area currently occupied by the species because we did not find any unoccupied areas to be essential for the conservation of the species. Based upon the recently completed recovery plan for the species, we have determined that the designation of critical habitat within the areas currently designated across the physiographic representation of each species' range will be sufficient to conserve the species. Efforts to improve the resiliency of populations in currently occupied streams, as discussed in the recovery plan, should increase viability to the point that protections of the Act are no longer necessary.

(6) Comment:

Multiple commenters suggested that the Service consider including additional areas as critical habitat that are adjacent to the proposed designation as these areas could impact the proposed critical habitat. Multiple commenters requested that we include additional areas upstream of proposed critical habitat. Specifically, one public commenter requested that critical habitat boundaries should be expanded to include riparian buffers, rather than limiting the designation of critical habitat to bank-full heights. In all instances, the commenters stated that alterations to riparian areas, headwater areas, or both could result in decreased suitability of designated critical habitat as a result of water quality or sedimentation impacts.

Our response:

Critical habitat includes areas that contain the physical or biological features essential to the conservation of the species, and which may require special management considerations or protection. We have identified those physical or biological features as adequate flows or suitable hydrological flow regimes, suitable substrates and connected instream habitats, adequate water and sediment quality, and the presence and abundance of suitable host fish (physical or biological features are described in more detail in the

Summary of Essential Physical or Biological Features

section, below). Although adjacent terrestrial areas may be important to maintaining the species' habitats, terrestrial areas would not themselves contain those aquatic features. Therefore, we are not including the terrestrial areas in the critical habitat designations.

We acknowledge that degradation to upstream reaches or riparian areas may affect downstream or within-stream areas of aquatic critical habitat. Actions with a federal nexus that may affect designated critical habitat would be considered through the Act's section 7 consultation processes. However, we also note and describe in the economic screening analysis that all areas designated as critical habitat for these four species of mussels are occupied; thus, section 7 consultation by Federal action agencies is already required for any activities that may affect the mussels regardless of critical habitat designation.

In recognition of the additional requirement in the Section 7 consultation associated with consideration of critical habitat, the costs of this additional layer of compliance due to the presence of critical habitat is quantified in the economic screening analysis. Because section 7 consultations would occur for projects with a Federal nexus that are planned within the critical habitat area anyway given that they are all occupied, there are already measures that would be implemented to avoid jeopardy to the species. Those measures that avoid jeopardy due to habitat impacts to the species are also likely to avoid adverse modification to critical habitat, minimizing any impact from the consultations on critical habitat. Indeed, we anticipate little to no additional section 7 consultations due solely to the designation of critical habitat and no new measures resulting from consultation on the critical habitat. Nevertheless, in our screening analysis for these mussels, we acknowledge the increased complexity of Section 7 consultations that consider critical habitat in addition to the species presence and quantify that administrative burden.

(7) Comment:

One commenter suggested that the Service include in the economic analysis consideration of the economic benefits of protecting critical habitat for the four mussel species, including ecosystem services, the protection of clean water, the reduced cost of water treatment for drinking water supplies, as well as public health and recreational benefits.

Our response:

The primary intended benefit of critical habitat is to support the conservation of endangered and threatened species, such as the rayed bean, sheepnose, snuffbox, and spectaclecase mussels. In order to quantify and monetize direct benefits of the designation, information would be needed to determine (1) the incremental change in the probability of conservation of these four species that is expected to result from the critical habitat designation, and (2) the public's willingness to pay for such beneficial changes. Because of the uncertainties associated with monetary quantification of these benefits and uncertainty in additional efforts to conserve any of these four species, we were not able to estimate the economic benefits of ecosystem services, such as clean water via mussel-based biofiltration treatment, or of broad benefits of ecosystem services that flow from the critical habitat areas to human populations.

(8) Comment:

One public commenter requested that we exclude critical habitat under section 4(b)(2) of the Act. Specifically, they requested that the Service consider excluding all agricultural and cultivated lands within the state of Tennessee from the proposed designation of critical habitat for sheepnose, snuffbox, and spectaclecase mussels. They stated that agriculture is the number one contributor to Tennessee's economy—accounting for 7.8 percent of the State's economic activity—and suggested that taking land out of production for use as critical habitat will reduce farmers' available resources to grow products, thus increasing the economic burden.

Our response:

We are only designating aquatic areas as critical habitat up to the ordinary high water mark; no areas used for agriculture or cultivation are included in the critical habitat designations. Furthermore, private activities without a federal nexus are not subject to additional restrictions due to critical habitat. Routine private land uses, like farming, ranching, timber harvest, and construction, carried out on private land without federal involvement are unaffected by critical habitat designations. Most agricultural activities do not have a Federal nexus, and there are no large-scale Federal irrigation projects in the range of these species. In those limited cases where agricultural activities have had a Federal nexus and have triggered consultation under section 7, there have been no formal consultations (

i.e.,

all consultations have concluded with a “may affect but are not likely to adversely affect” determination). Thus, we do not anticipate any agricultural areas being taken out of production or otherwise restricted due to this designation.

(9) Comment:

Multiple commenters expressed concerns that these critical habitat designations would impose restrictions on private lands, or public lands, and result in loss of access to or ability to use areas designated as critical habitat. One commenter expressed specific concerns that such restrictions would take areas that are currently agricultural and cultivated lands out of production and would result in decreased agricultural productivity.

Our response:

Under the Act, the only regulatory effect of a critical habitat designation is that Federal agencies must ensure their actions are not likely to destroy or adversely modify critical habitat under section 7 of the Act. The Act does not authorize the Service to regulate private actions on private lands or confiscate private property as a result of critical habitat designation. Designation of critical habitat does not affect land ownership. Critical habitat designation also does not establish specific land management standards or prescriptions, although Federal agencies are prohibited from carrying out, funding, or authorizing actions that would destroy or adversely modify critical habitat. Destruction or adverse modification means a direct or indirect alteration that appreciably diminishes the value of critical habitat for the conservation of a listed species. Most projects that impact critical habitat do not destroy or adversely modify it. In those limited cases where the proposed action would destroy or adversely modify the critical habitat, the Service is required to identify reasonable and prudent alternatives to the proposed action that would avoid destruction and adverse modification. Reasonable and prudent alternatives must be economically and technologically feasible and implemented in a manner consistent with the intended purposes of the action.

The designation of critical habitat does not prevent access to any land, whether private, tribal, State or Federal. Critical habitat receives protection only under section 7 of the Act and only directs Federal agencies to ensure, in consultation with the Service, that any action they authorize, fund, or carry out is not likely to result in the destruction or adverse modification of critical habitat. The designation of critical habitat does not affect land ownership or establish a refuge, wilderness, reserve, preserve, or other conservation area. Such designation does not allow the government or public to access private lands. Such designation does not require implementation of restoration, recovery, or enhancement measures by non-Federal landowners. Lastly, the areas designated as critical habitat only include aquatic habitat up to the ordinary high water mark; adjacent, terrestrial riparian areas (

i.e.,

those areas used for agriculture or cultivation) are not included as part of the critical habitat designations. Therefore, these final designations of critical habitat will not remove agricultural and cultivated lands from production and will not result in loss of access to areas of private or public lands.

(10) Comment:

One commenter provided information that supports the effectiveness of forestry best management practices (BMPs) on reducing sedimentation and erosion and protecting aquatic biota. The commenter recommended that we include this information in the final rule.

Our response:

We identified the use of BMPs to reduce sedimentation, erosion, and bank destruction as one of the management activities that could ameliorate those threats to the physical or biological features in Special Management Considerations or Protection in the proposed rule (see 89 FR 101100 at 101106, December 13, 2024) and in the same discussions (below) in this final rule.

I. Critical Habitat

Background

Section 4(a)(3) of the Act requires that, to the maximum extent prudent and determinable, we designate a species' critical habitat concurrently with listing the species. Critical habitat is defined in section 3(5)(A) of the Act as:

(1) The specific areas within the geographical area occupied by the species, at the time it is listed in accordance with the Act, on which are found those physical or biological features

(a) Essential to the conservation of the species, and

(b) Which may require special management considerations or protection; and

(2) Specific areas outside the geographical area occupied by the species at the time it is listed, upon a determination that such areas are essential for the conservation of the species.

Our regulations at 50 CFR 424.02 define the geographical area occupied by the species as an area that may generally be delineated around species' occurrences, as determined by the Secretary (

i.e.,

range). Such areas may include those areas used throughout all or part of the species' lifecycle, even if not used on a regular basis (

e.g.,

migratory corridors, seasonal habitats, and habitats used periodically, but not solely by vagrant individuals).

Conservation, as defined under section 3(3) of the Act, means to use and the use of all methods and procedures that are necessary to bring an endangered or threatened species to the point at which the measures provided pursuant to the Act are no longer necessary. Such methods and procedures include, but are not limited to, all activities associated with scientific resources management such as research, census, law enforcement, habitat acquisition and maintenance, propagation, live trapping, and transplantation, and, in the extraordinary case where population pressures within a given ecosystem cannot be otherwise relieved, may include regulated taking.

Critical habitat receives protection under section 7 of the Act through the requirement that each Federal action agency ensure, in consultation with the Service, that any action they authorize, fund, or carry out is not likely to result in the destruction or adverse modification of designated critical habitat. The designation of critical habitat does not affect land ownership or establish a refuge, wilderness, reserve, preserve, or other conservation area. Such designation also does not allow the government or public to access private lands. Such designation does not require implementation of restoration, recovery, or enhancement measures by non-Federal landowners. Rather, designation requires that, where

a landowner requests Federal agency funding or authorization for an action that may affect an area designated as critical habitat, the Federal agency consult with the Service under section 7(a)(2) of the Act. If the action may affect the listed species itself (such as for occupied critical habitat), the Federal action agency would have already been required to consult with the Service even absent the designation because of the requirement to ensure that the action is not likely to jeopardize the continued existence of the listed species. Even if the Service were to conclude after consultation that the proposed activity is likely to result in destruction or adverse modification of the critical habitat, the Federal action agency and the landowner are not required to abandon the proposed activity, or to restore or recover the species; instead, they must implement “reasonable and prudent alternatives” to avoid destruction or adverse modification of critical habitat. By definition (50 CFR 402.02), reasonable and prudent alternatives are not allowed to make projects infeasible (see response to comment 9).

Under the first prong of the Act's definition of critical habitat, areas within the geographical area occupied by the species at the time it was listed are included in a critical habitat designation if they contain physical or biological features (1) which are essential to the conservation of the species and (2) which may require special management considerations or protection. For these areas, critical habitat designations identify, to the extent known using the best scientific data available, those physical or biological features that are essential to the conservation of the species (such as space, food, cover, and protected habitat).

Under the second prong of the Act's definition of critical habitat, we can designate critical habitat in areas outside the geographical area occupied by the species at the time it is listed, upon a determination that such areas are essential for the conservation of the species.

Section 4(b)(2) of the Act requires that we designate critical habitat on the basis of the best scientific data available. Further, our Policy on Information Standards Under the Endangered Species Act (published in the

Federal Register

on July 1, 1994 (59 FR 34271)), the Information Quality Act (section 515 of the Treasury and General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658)), and our associated Information Quality Guidelines provide criteria, establish procedures, and provide guidance to ensure that our decisions are based on the best scientific data available. They require our biologists, to the extent consistent with the Act and with the use of the best scientific data available, to use primary and original sources of information as the basis for recommendations to designate critical habitat.

When we are determining which areas should be designated as critical habitat, our primary source of information is generally the information compiled in the SSA report and information developed during the listing process for the species. Additional information sources may include any generalized conservation strategy, criteria, or outline that may have been developed for the species; the recovery plan for the species; articles in peer-reviewed journals; conservation plans developed by States and counties; scientific status surveys and studies; biological assessments; other unpublished materials; or experts' opinions or personal knowledge.

A critical habitat designation does not signal that habitat outside the designated area is unimportant or may not be needed for recovery of the species. Areas that are important to the conservation of the species, both inside and outside the critical habitat designation, will continue to be subject to: (1) Conservation actions implemented under section 7(a)(1) of the Act; (2) regulatory protections afforded by the requirement in section 7(a)(2) of the Act for Federal agencies to ensure their actions are not likely to jeopardize the continued existence of any endangered or threatened species; and (3) the prohibitions found in section 9 of the Act. These protections and conservation tools will continue to contribute to recovery of the species. Similarly, critical habitat designations made on the basis of the best scientific data available at the time of designation will not control the direction and substance of future recovery plans, habitat conservation plans (HCPs), or other species conservation planning efforts if new information available at the time of those planning efforts calls for a different outcome.

Physical or Biological Features Essential to the Conservation of the Species

In accordance with section 3(5)(A)(i) of the Act and regulations at 50 CFR 424.12(b), in determining which areas we will designate as critical habitat from within the geographical area occupied by the species at the time of listing, we consider the physical or biological features that are essential to the conservation of the species and which may require special management considerations or protection. The regulations at 50 CFR 424.02 define “physical or biological features essential to the conservation of the species” as the features that occur in specific areas and that are essential to support the life-history needs of the species, including, but not limited to, water characteristics, soil type, geological features, sites, prey, vegetation, symbiotic species, or other features. A feature may be a single habitat characteristic or a more complex combination of habitat characteristics. Features may include habitat characteristics that support ephemeral or dynamic habitat conditions. Features may also be expressed in terms relating to principles of conservation biology, such as patch size, distribution distances, and connectivity. For example, physical features essential to the conservation of the species might include gravel of a particular size required for spawning, alkaline soil for seed germination, protective cover for migration, or susceptibility to flooding or fire that maintains necessary early-successional habitat characteristics. Biological features might include prey species, forage grasses, specific kinds or ages of trees for roosting or nesting, symbiotic fungi, or absence of a particular level of nonnative species consistent with conservation needs of the listed species. The features may also be combinations of habitat characteristics and may encompass the relationship between characteristics or the necessary amount of a characteristic essential to support the life history of the species.

In considering whether features are essential to the conservation of the species, we may consider an appropriate quality, quantity, and spatial and temporal arrangement of habitat characteristics in the context of the life-history needs, condition, and status of the species. These characteristics include, but are not limited to, space for individual and population growth and for normal behavior; food, water, air, light, minerals, or other nutritional or physiological requirements; cover or shelter; sites for breeding, reproduction, or rearing (or development) of offspring; and habitats that are protected from disturbance.

General Mussel Biology

Freshwater mussels, including the rayed bean, sheepnose, snuffbox, and spectaclecase mussels, have a complex life history that involves parasitic larvae, called glochidia, which are wholly reliant on host fish(es). As adult

freshwater mussels are generally sessile, suspension-feeders that spend their entire lives partially or completely buried within the substrate (Call 1900, p. 459; Watters 1994, p. 105; West et al. 2000, p. 251), dispersal occurs solely through the behavior of their host fish(es). Mussels are broadcast spawners; males release sperm into the water column, which is taken in by the female. Fertilized eggs develop into microscopic larvae called glochidia within special gill chambers on the female mussel and remain with the female until they are mature and ready for release as glochidia, to attach to their host fish(es) (Haag 2012, pp. 37-42).

Glochidia will perish if they fail to attach to a suitable species of host fish, attach to a fish that has developed immunity from prior infestations, or attach to the wrong location on a host fish (Neeves 1991, p. 254; Bogan 1993, p. 599). Successful glochidia encyst (enclose in a cyst-like structure) on the host's tissue, draw nutrients from the host's tissue, and develop into juvenile mussels (Arey 1932, pp. 214-215). After a period of time when the glochidia transform into juveniles, they will excyst (drop off) from the fish and drop to the substrate on the bottom of the stream. Juveniles that drop in unsuitable substrates perish because their immobility prevents them from relocating to more favorable habitat. Juveniles burrow into interstitial substrates and grow to larger sizes that are less susceptible to predation and displacement from high-flow events (Yeager et al. 1994, p. 220). Adult mussels remain within the same general location where they excysted from their host fish as juveniles.

Habitat Conditions, Suitable Substrates, and Flow Conditions

All life stages of the rayed bean, sheepnose, snuffbox, and spectaclecase mussels require flowing water for survival. In general, all four species occur within small- to medium-sized creeks, to larger rivers, with rayed bean and snuffbox occasionally occurring along wave-washed shores of lakes (Call 1900, p. 459; Ortman 1919, p. 68; Stansbery 1967, entire; Buchanan 1980, p. 13; Neeves 1991, pp. 280-281; Cummings and Mayer 1992, pp. 50, 142, 162; Watters 1994, p. 105; Oesch 1995, p. 121; Parmalee and Bogan, 1998; pp. 50, 77, 108, 177, 244; Baird 2000, p. 5-6; West et al. 2000, pp. 251, 253; Badra 2002, pers. comm.; Butler 2002, p. 6; Williams et al. 2008, p. 498; Jones et al. 2019, p. 205). Within these areas, rayed bean typically occur in or near shoal or riffle (short, shallow length of stream where the stream flows more rapidly) areas and in the shallow wave-washed areas of glacial lakes over gravel and sand substrates (West et al. 2000, p. 253). Sheepnose typically occur in shallow shoal habitats with moderate to swift currents—ranging from riffles of a few inches in depth to runs that exceed 20 feet (6 meters) in larger rivers—over mixtures of coarse sand, gravel, and clay (Ortman 1919, p. 68; Cummings and Mayer 1992, p. 50; Oesch 1995, p. 121; Parmalee and Bogan 1998, pp. 77, 177; Jones et al. 2019, p. 205). Snuffbox typically occur in swift currents of riffles and shoals in rivers and streams and the wave-washed shores of lakes over gravel and sand with occasional cobble and boulders (Cummings and Mayer 1992, p. 162; Parmalee and Bogan 1998, p. 108). Spectaclecase typically occur in rivers and streams with slow to swift currents—often in quiet water near the interface of swift currents—over substrates that range from mud and sand to gravel, cobble, and boulders within relatively shallow riffles and shoals (Stansbery 1967, pp. 29-30; Buchanan 1980, p. 13; Parmalee and Bogan 1998, p. 50; Baird 2000, pp. 5-6).

Appropriate flow is critical for delivering oxygen and nutrients for respiration and filtration (

i.e.,

survival and growth), essential for reproduction to allow glochidia to move to their host and encyst, as well as removing silt and other fine sediments from within rock structures and crevices, which prevents mussel suffocation and degradation of mussel and host-fish shelter habitats. Normal fluctuations in flow velocity are expected; however, extreme changes can be detrimental. Significant or prolonged increases in velocity, typically associated with flood conditions, have the potential to dislodge and scour mussels and move the bed, destroying habitat for the mussels and their host fishes (Holland-Bartels 1990, pp. 331-332; Layzer and Madison 1995, p. 135). Further, abnormally high velocities have the potential to cause glochidia mortality due to wash out and displacement of juveniles and adults. Alternatively, extreme low flows, typically associated with drought or water withdrawals, can impact reproduction, feeding, respiration, and in some cases, result in exposure and desiccation of the species (Fisher and LaVoy 1972, pp. 1473-1476; Stegman 2020, entire). Although some individuals are found in areas that experience seasonal low flows, areas that experience periodic drying or intermittent flow generally cannot support mussel assemblages.

Appropriate water quality is critical to the survival, reproduction, and persistence of all life stages of freshwater mussels. Point and non-point source contaminants can result in water quality and habitat degradation. Contaminants alter the chemical, physical, and biological characteristics of a stream, resulting in lethal and sub-lethal effects to mussels and their fish hosts. Although specific data for these parameters with respect to these four species are not directly available, mussels in general are similar in terms of sensitivity to certain thresholds, depending on the life stage exposed. In general, mussels need water temperatures below 86 degrees Fahrenheit (30 degrees Celsius), dissolved oxygen concentrations greater than 5 milligrams per liter (Pandolfo 2010, entire), and water quality concentrations below acute toxicity levels to mussels for contaminants such as total ammonia, nitrogen, copper, chloride, and sulfate (see Appendix B, Service 2022a, b, c, d).

Habitat Connectivity

A mussel population includes more than one mussel bed; it is the collection of mussel beds within a stream reach between which infested host fish may travel, allowing for ebbs and flows in mussel bed density and abundance through time throughout the population's occupied reach. Therefore, sufficiently resilient populations of all four species must occupy connected stream reaches long enough so that stochastic events that affect individual mussel beds do not eliminate the entire population. Connectivity is characterized by suitable water quality, lack of barriers to dispersal (

e.g.,

perched culverts, hydropower dams that lack passage for host fishes, water control structures), and presence of suitable shelter habitat and forage base for host fish(es). Repopulation, through dispersal via infected host fish from other mussel beds within a given stream reach, can allow the population and individual beds within that population to recover from these stochastic events. Long stream reaches are more likely to support sufficiently resilient populations into the future than shorter stream reaches; thus, long reaches of connected stream habitat are essential to support all life stages of all four species.

Presence of Host Fish Species

All four species are obligate parasites that rely on specific host-fish for developing into juvenile mussels and dispersal. Glochidia must come into contact with specific host fish to ensure survival; without the proper host fish, glochidia will perish and fail to transform into juvenile mussels. Each

mussel species relies on a different suite of host fish(es).

Rayed bean depend on darter and sculpin species as host fish; however, the exact suite of host fish species is unknown (Parmalee and Bogan, 1998, p. 245; West et al. 2000, p. 254). The only published studies identify the Tippecanoe darter (

Etheostoma tippecanoe

) and spotted darter (

E. maculatum

) as host fish (White et al. 1996, p. 191; Gibson et al. 2011, p. 7); however, these species are not (and were not) found throughout the species' current or historical range. Other host fishes are thought to include the greenside darter (

E. blenniodes

), rainbow darter (

E. caeruleum

), mottled sculpin (

Cottus bairdi

), and largemouth bass (

Micropterus salmoides

) (Woolnough 2002, p. 51). Based on closely related species that occur in the same areas and habitats, additional hosts may include species in the subgenus

Nothonotus

of

Etheostoma,

sculpins (

Cottus

spp.), and fantail darter (

E. flabellare

) (Jones 2002, pers. comm.).

Sheepnose depend on mimic shiner (

Notropis volucellus

) and sauger (

Sander canadensis

) as host fish; of these, only mimic shiner has been observed to be naturally infested and successfully facilitate transformation of juveniles in the lab and is most likely the primary host species. However, lab studies suggest that sheepnose may be able to use a wider variety of fish species including fathead minnow (

Pimephales promelas

), creek chub (

Semotilus atrromaculatus

), central stoneroller (

Campostoma anomalum

), brook stickleback (

Culaea inconstans

), and golden shiner (

Notemigonus cryoleucas

) (Watters et al. 2005, pp. 11-12; Bradley 2021, pers. comm.).

Snuffbox mussels rely on darter and sculpin species as fish hosts, using log perch (

Percina caprodes

) as their primary host species. Female snuffbox lure host fish with an inflated mantle (

i.e.,

lure) and close their shell around the head of the fish long enough to expel their glochidia and allow for their attachment to the gills of the fish, before releasing the fish (Schwalb et al. 2011, p. 224). Given this life history strategy, they rely on clear water that allows their lures to be visible by potential fish hosts. Other potential host species from lab studies include the blackside darter (

P. maculata

), rainbow darter, Iowa darter (

E. exile

), blackspotted topminnow (

Fundulus olivaceous

), mottled sculpin, banded sculpin (

C. carolinae

), Ozark sculpin (

C. hypselurus

), largemouth bass, and brook stickleback (Sherman 1994, p. 17, Yeager and Saylor 1995, p. 3; Hillegass and Hove 1997, p. 25; Barnhart et al. 1998, p. 34; Hove et al. 2000, p. 30; Sherman Mulcrone 2004, pp. 100-103).

Spectaclecase depend on mooneye (

Hiodon tergisus

) and goldeye (

Hiodon alosoides

) as host fishes (Sietman et al. 2017, p. 18). Natural infestations of spectaclecase have been observed on bigeye chub (

Hybopsis amblops

) and pealip redhorse (

Moxostoma pisolabrum

); however, they are not confirmed host fish species because juvenile mussels have not been observed transforming from these species in lab studies (Baird 2000, p. 24).

Summary of Essential Physical or Biological Features

We derive the specific physical or biological features essential to the conservation of the rayed bean, sheepnose, snuffbox, and spectaclecase from studies of the species' habitat, ecology, and life history as described above. Additional information can be found in the SSA report for each species (Service 2022a, pp. 3-10; Service 2022b, pp. 4-13; Service 2022c, pp. 3-11; Service 2022d, pp. 4-11; all SSA reports are available on

https://www.regulations.gov

at Docket No. FWS-R3-ES-2024-0144) and on the Service's website at the respective species' profile pages (see

Availability of supporting materials

under

ADDRESSES

, above). The primary habitat features that support resiliency of the four mussel species include flow regime, habitat connectivity, water and sediment quality, and the presence of host fish species. The link between these habitat features and the needs of each life stage of the four mussel species is summarized in table 1, below.

Table 1—Habitat Requirements for Each Life Stage of the Four Mussel Species

Life stage

Supporting habitat or biological features

Reference

Fertilized eggs

• Suitable water quality

• Sexually mature males in proximity to sexually mature females.

• Suitable spawning water temperatures.

• Suitable flow conditions.

Ortman 1919, p. 66; Fuller 1974, pp. 240-241; Berg et al. 2008, p. 397; Haag 2012, pp. 38-39.

Glochidia

• Suitable water quality (clear water for visual attraction of host)

• Availability of host fish for attachment.

○ Rayed bean: darter and sculpin species.

○ Sheepnose: mimic shiner (

Notropis volucellus

) and sauger (

Sander canadensis

).

○ Snuffbox: logperch (

Percina caprodes

) and darter and sculpin species.

○ Spectaclecase: mooneye (

Hiodon tergisus

) and goldeye (

H. alosoides

).

• Suitable water temperature.

• Suitable flow conditions to ensure glochidia encounter host.

Fuller 1974, pp. 240-241; Strayer 2008, p. 65; Guenther et al. 2009, p. 20; Haag 2012, pp. 41-42; Wolf et al. 2012, p. 7; Hove et al. 2015, pp. 4, 6-8, 12-13.

Juveniles

• Suitable water quality (appropriate interstitial chemistry, low salinity, low ammonia, low copper and other contaminants, high dissolved oxygen).

• Suitable water temperature.

• Suitable flow conditions.

• Host fish dispersal.

• Food availability: smaller algae, detritus, bacteria, organic matter, pedal feeding for first several months.

• Suitable substrate conditions:

○ Rayed bean and snuffbox: stable sand and gravel.

○ Sheepnose: firm/stable; coarse sand and gravel; cobble; may include mud.

○ Spectaclecase: firm/stable; coarse sand, gravel, and rock free from excessive silt; may include large slabs/boulders.

Ortman 1919, p. 68; Fuller 1974, pp. 220-221, 238-246; Cummings and Mayer 1992, p. 50; Dimock and Wright 1993, pp. 188-190; Yeager et al. 1994, p. 221; Sparks and Strayer 1998, p. 132; Augspurger et al. 2003, p. 2,574; Augspurger et al. 2007, p. 2,025; Schwalb et al. 2011, entire; Strayer and Malcom 2012, pp. 1,787-1,788; Watters et al. 2009, p. 221.

Adults

• Suitable water quality (appropriate interstitial chemistry, low salinity, low ammonia, low copper and other contaminants, high dissolved oxygen).

• Suitable water temperature.

• Suitable flow conditions.

• Food availability: algae, detritus, bacteria, dissolved organic matter, microscopic animals.

• Suitable substrate conditions:

○ Rayed bean and snuffbox: stable sand and gravel.

○ Sheepnose: firm/stable; coarse sand and gravel; cobble; may include mud.

○ Spectaclecase: firm/stable; coarse sand, gravel, and rock free from excessive silt; may include large slabs/boulders.

Ortmann 1919, p. 68; Fuller 1974, pp. 221, 240-246; Cummings and Mayer 1992, p. 50; Yeager et al. 1994, p. 221; Parmalee and Bogan 1998, p. 177; Nichols and Garling 2000, p. 881; Chen et al. 2001, pp. 213-214; Spooner and Vaughn 2008, p. 308; Watters et al. 2009, p. 221.

We have determined that the following physical or biological features are essential to the conservation of the rayed bean, sheepnose, snuffbox, and spectaclecase:

(i) Adequate flows, or a hydrological flow regime (magnitude, timing, frequency, duration, rate of change, and overall seasonality of discharge over time), necessary to maintain benthic habitats where the species are found and to maintain stream connectivity.

(ii) Suitable substrates and connected instream habitats, characterized by geomorphologically stable stream channels and banks (

i.e.,

channels that maintain lateral dimensions, longitudinal profiles, and sinuosity patterns over time without an aggrading or degrading bed elevation) that support the four mussel species and their respective host fishes. For rayed bean and snuffbox, suitable substrates are stable gravel and sand with moderate flow and aquatic vegetation in and adjacent to riffles and shoals. For sheepnose, suitable substrates are firm or stable coarse sand, gravel, or rock free from excessive silt. For spectaclecase, these substrates are firm or stable substrates of coarse sand and gravel, are free from excessive silt, and typically include large rock, slabs, or boulders.

(iii) Water and sediment quality necessary to sustain natural physiological processes for normal behavior, growth, and viability of all life stages, including appropriate levels of dissolved oxygen (generally above 2 to 3 parts per million (ppm)), salinity (generally below 2 to 4 ppm), and temperature (generally below 86 degrees Fahrenheit (°F) (30 degrees Celsius (°C))). Additionally, concentrations of contaminants, including (but not limited to) ammonia, nitrate, copper, and chloride, are below acute toxicity levels for mussels.

(iv) The presence and abundance of host fishes necessary for recruitment of the species. For the rayed bean, these are darter and sculpin species; for the sheepnose, these are mimic shiner (

Notropis volucellus

) and sauger (

Sander canadensis

); for the snuffbox, these are logperch (

Percina caprodes

) and darter and sculpin species; and for the spectaclecase, these are mooneye (

Hiodon tergisus

) and goldeye (

H. alosoides

).

Special Management Considerations or Protection

When designating critical habitat, we assess whether there are specific areas within the geographical area occupied by the species at the time of listing containing physical or biological features which (1) are essential to the conservation of the species, and (2) may require special management considerations or protection.

The features essential to the conservation of the rayed bean, sheepnose, snuffbox, and spectaclecase may require special management considerations or protection to reduce the following threats: (1) construction or operation of reservoirs; (2) urbanization of the landscape, including (but not limited to) land conversion to impervious surfaces for urban and commercial use, infrastructure (pipelines, roads, bridges, utilities), and wastewater treatment; (3) significant alteration of water quality and nutrient pollution from a variety of activities, such as mining and agricultural activities; (4) land-use activities that remove large areas of forested wetlands and riparian systems; (5) culvert, dam, and pipe installation that creates barriers to movement for the mussels or their host fish; and (6) other watershed and floodplain disturbances that release sediments, pollutants, or nutrients into the water.

Management activities that could ameliorate these threats include, but are not limited to, implementation of best management practices (for silvicultural and agricultural land uses) designed to reduce sedimentation, erosion, and bank destruction; implementation of habitat restoration projects; protection of riparian corridors and woody vegetation; and modification of dam operations or dam removal or both to more closely match natural flow regimes; improved stormwater management; and reduction of other watershed and floodplain disturbances that release sediments, pollutants, or nutrients into the water.

Criteria Used To Identify Critical Habitat

As required by section 4(b)(2) of the Act, we use the best scientific data available to designate critical habitat. In accordance with the Act and our implementing regulations at 50 CFR 424.12(b), we review available information pertaining to the habitat requirements of the species and identify specific areas within the geographical area occupied by the species at the time of listing and any specific areas outside the geographical area occupied by the species to be considered for designation as critical habitat. We are not designating any areas outside the geographical area occupied by the species because we have not identified any unoccupied areas that meet the definition of critical habitat, and we have determined that occupied areas are sufficient to conserve these four species. Within the recovery plans for all four species, we outline that recovery can be achieved by protecting and maintaining or enhancing existing occupied areas, with no need to create or establish new habitat areas or populations for all four species. Thus, the designation includes only the occupied rivers and streams within the species' ranges that contain the physical or biological features essential to the conservation of the species and that provide the best conditions for the maintenance and expansion of existing populations.

Methodology Used for Selection of Critical Habitat Units

First, we identified those areas within the geographical areas occupied by the species at the time of listing that contain the essential physical or biological features and determined which of these features may require special management considerations or protection. Across all species, we included the areas where the high-condition populations—defined in the SSA report as populations with stable to increasing demography and known evidence of recent recruitment thus indicating a high estimated probability of persistence—occur because these are the areas that contain the features that currently meet the four species' needs for maintaining viability. The presence of the essential physical or biological features in these areas result in populations that have recruitment, varied age class structures, and high-density populations that are important to conservation and recovery actions, as they may serve to bolster other diminished or extirpated populations.

Second, we examined the overall contribution of moderate-condition populations—defined in the SSA report as populations with stable to slightly decreasing demography with limited evidence of recruitment, thus indicating a moderate probability of persistence—to viability of the species, as well as the level of threats acting on those populations. We then considered adjacency and connectivity of these moderate-condition populations to the high-condition and other moderate-condition populations and included moderate-condition areas on a case-by-case basis. We did not include populations that have potentially low likelihood of recovery due to limited abundances, currently have high levels of threats acting on the species and its habitat, or lack of connectivity to other high- or moderate-condition populations. We did not include areas that do not contain the essential physical or biological features.

Third, we evaluated spatial redundancy and representation across each of the four species' ranges to identify any remaining, consistently observable populations in a major river basin that may contain unique diversity or habitat or both. If we identified such populations, we included them in this final critical habitat designation. For instance, the lower Mississippi River Basin is comprised of a single population of sheepnose within the Big Sunflower River of Bolivar and Sunflower Counties, Mississippi; this population is in low condition. However, this population exists at the southern edge of the species' range and may have unique genetic diversity that is not present elsewhere within the species' range, and this unit contains one or more of the essential physical or biological features. Thus, we include this stream segment in the sheepnose's final critical habitat designation to enhance the likelihood of maintaining genetic diversity.

Finally, we evaluated the overlap of the four species' occurrences, as well as their overlap with other listed aquatic species and designated critical habitat, where existing conservation and monitoring efforts may be ongoing. In areas with a high degree of overlap or existing conservation efforts, we included areas of critical habitat within the overlapping areas. These areas were considered in formulating this final critical habitat designation because they contain the physical or biological features that are essential to the conservation of the species and that may require special management considerations. These areas may promote conservation and recovery through maintaining the ecological community and existing genetic diversity for the species.

For all critical habitat units, we define the upstream and downstream boundaries around areas that were occupied by the species at the time of listing and that contain the physical or biological features essential to the conservation of the species using easily recognizable features (

e.g.,

confluence of two named streams, impoundments).

Sources of data for these final critical habitat designations include multiple databases maintained by universities, information from State agencies throughout the species' ranges, and numerous survey reports on threats throughout the species' ranges (as cited in Service 2022a, entire; Service 2022b, entire; Service 2022c, entire; Service 2022d, entire; all reports are available on

https://www.regulations.gov

at Docket No. FWS-R3-ES-2024-0144). We also reviewed available information that pertains to the habitat requirements for these species. Sources of information on habitat requirements include studies conducted at occupied sites and published in peer-reviewed articles, agency reports, and data collected during monitoring efforts (as cited in Service 2022a, entire; Service 2022b, entire; Service 2022c, entire; Service 2022d, entire; all reports are available on

https://www.regulations.gov

at Docket No. FWS-R3-ES-2024-0144). River segments were defined using the National Hydrography Dataset Plus High Resolution (NHDPlus HR) dataset maintained by the U.S. Geological Survey (Moore et al. 2019, entire).

In summary, for areas within the geographical area occupied by the species at the time of listing, we delineated critical habitat unit boundaries using the following criteria:

(1) We identified river and stream reaches with observations from 2000 to present for rayed bean, sheepnose, and snuffbox, as well as river and stream reaches with observations from 1970 to present for spectaclecase, and considered these areas to be currently occupied. For spectaclecase, we determined that it is reasonable to find these areas occupied over a longer timeframe due to its longer lifespan (50 or more years on average), compared to the other mussel species (less than 30 years on average). For all species, the available State heritage databases and information, as well as increased survey efforts and detections of the species since 2012 in previously unknown areas of suitable habitat, support the likelihood of the species' continued presence in known occupied areas since the time of listing in 2012.

(2) We delineated specific habitat areas based on Natural Heritage Element Occurrences, published reports, and unpublished survey data provided by States and other partners. These areas provide habitat for the four mussel species, despite fluctuations in local conditions. The areas within the proposed units represent continuous river and stream reaches of relatively free-flowing habitat patches capable of sustaining fish hosts and allowing for transport of glochidia, which are essential for reproduction and dispersal of these species.

(a)

Rayed bean:

We are designating critical habitat for the rayed bean in the Black River, Pine River, Belle River, River Raisin, Clinton River, Fish Creek, Swan Creek, Blanchard River, Allegheny River, Olean Creek, Oil Creek, Oswayo Creek, French Creek, LeBoeuf Creek, Muddy Creek, Cussewago Creek, Little Darby Creek, Big Darby Creek, Great Miami River, and Tippecanoe River (see Final Critical Habitat Designation, below). All of these rivers and streams were known to be occupied at the time of listing except River Raisin, Oil Creek, Oswayo Creek, and Little Darby Creek. Although the rayed bean was not known from River Raisin (detected in 2015), Oil Creek (detected in 2015), Oswayo Creek (detected in 2015), and Little Darby Creek (detected in 2023) at the time of listing, all of the rivers and streams are either tributaries to or occur within a watershed where the rayed bean was known to occur at the time of listing, except for River Raisin. Eight adult rayed bean were detected in the River Raisin in 2015, representing an occurrence in an entirely new watershed that was not known to be occupied at the time of listing. Given that the species is able to live in excess of 20 years, juvenile and adult mussels are immobile, adults mature around age 4 or 5, and the detections were of reproducing adults of unknown ages, it is reasonable to assume that these watersheds were also occupied at the time of listing in 2012 and had not been detected due to lack of survey effort. Thus, we consider all units to have been occupied at the time of listing and appropriate for designation as occupied critical habitat. Furthermore, given that the mussel beds within River Raisin, Oil Creek, Oswayo Creek, and Little Darby Creek are considered currently occupied and fall within the currently extant range for the species (

i.e.,

wherever found), we would consult on any activities that are occurring or that will occur within these areas of the species' range.

(b)

Sheepnose:

We are designating critical habitat for the sheepnose in the Chippewa River, Kankakee River, Meramec and Bourbeuse Rivers, Allegheny River, Green River, Tippecanoe River, Walhonding River, Tennessee River, Clinch River, Powell River, and Big Sunflower River (see Final Critical Habitat Designation, below). All of these rivers and streams were known to be occupied at the time of listing.

(c)

Snuffbox:

We are designating critical habitat for the snuffbox in the Wolf River, Embarrass River, Little Wolf River, Grand River (Michigan), Flat River, Clinton River, Huron River, Grand River (Ohio), West Branch Grand River (Ohio), Allegheny River, French Creek, LeBoeuf Creek, Cussewago Creek, Woodcock Creek, Muddy Creek, Conneaut Outlet, West Fork River, Shenango River, Little Shenango River, Middle Island Creek, Meathouse Fork, McElroy Creek, Little Kanawha River, Leading Creek, Hughes River, North Fork Hughes River, South Fork Hughes River, Kanawha River, Elk River (West Virginia), Olentangy River, Little Darby Creek, Big Darby Creek, Stillwater River, Tygarts Creek, Kinniconick Creek, Licking River, Slate Creek, Middle Fork Kentucky River, Red Bird River, Red River, Green River, Salamonie River, Tippecanoe River, Embarras River, Rolling Fork Salt River, Clinch River, Powell River, Paint Rock River, Elk River (Tennessee), Duck River, St. Croix River, Meramec River, Bourbeuse River, St. Francis River, and Spring River (see Final Critical Habitat Designation, below). All of these rivers and streams were known to be occupied at the time of listing except for Cussewago Creek, West Fork River, Meathouse Fork, South Fork Hughes River, Leading Creek, and Kanawha River. Although the snuffbox was not reported from or detected in Cussewago Creek (detected in 2011; reported post-listing), West Fork River (detected in 2020), Meathouse Fork (detected in 2001; reported in 2016), South Fork Hughes River (detected in 2001; reported in 2016), Leading Creek (detected in 2017), and Kanawha River (detected in 2017) prior to the snuffbox's listing in 2012, all of the rivers and streams are either tributaries to or occur within the watershed where the snuffbox was known to occur at the time of listing. In Cussewago Creek, a fresh dead adult was detected in 2011, but this observation was not reported to the Service until after the species was listed. In West Fork River, three live adults were found in 2020. In the Meathouse Fork and South Fork Hughes River, live snuffbox were detected in 2001, but the data were not reported to the Service until 2016. Follow up surveys in the South Fork Hughes River in 2017 found live individuals dispersed across 24 miles (39 kilometers) of river. In Leading Creek, although the species was presumed extirpated from this reach at the time of listing, one live individual was detected in 2017. Finally, in the Kanawha River, although the species was thought to be extirpated from this reach at the time of listing, one live individual was detected in 2017. Regarding the Cussewago Creek, Meathouse Fork, and South Fork Hughes River, snuffbox was extant in these areas at the time of listing in 2012; however, these data were not provided to the Service until after the species was listed. Regarding all rivers—including the West Fork River, Leading Creek, and Kanawha River—given that all mussel beds occur within areas that are connected to known occupied areas, the species is known to live in excess of 20 years, juvenile and adult mussels are immobile, adults mature around age 5, and many of these detections were of reproducing adults, it is reasonable to assume that these areas were occupied at the time the species was listed in 2012. As such, we consider all units to be occupied at the time of listing and appropriate for designation as occupied critical habitat. Furthermore, given that the mussel beds within Cussewago Creek, West Fork River, Meathouse Fork, South Fork Hughes River, Leading Creek, and Kanawha River are considered to be currently occupied and fall within the currently extant range for the species (

i.e.,

wherever found), we would consult on any activities that are occurring or that will occur within these areas of the species' range.

(d)

Spectaclecase:

We are designating critical habitat for the spectaclecase in the St. Croix River, Mississippi River, Meramec River, Big River, Gasconade River, Big Piney River, Ouachita River, Tennessee River, Clinch River, Nolichucky River, Green River, and Kanawha River (see Final Critical Habitat Designation, below). All of these rivers and streams were known to be occupied at the time of listing.

When determining critical habitat boundaries, we made every effort to avoid including developed areas such as lands covered by buildings, pavement, and other structures because such lands lack physical or biological features necessary for the rayed bean, sheepnose, snuffbox, and spectaclecase. Critical habitat for these mussels includes only stream channels up to bankfull height, where the stream base flow is contained within the channel. The scale of the maps we prepared under the parameters

for publication within the Code of Federal Regulations may not reflect the exclusion of such developed lands. Any such lands inadvertently left inside critical habitat boundaries shown on the maps of this rule have been excluded by text in the rule and are not designated as critical habitat. Therefore, a Federal action involving these lands (and not affecting the designated critical habitat) will not trigger section 7 consultation with respect to critical habitat and the requirement of no adverse modification unless the specific action will affect the physical or biological features in the adjacent critical habitat.

The critical habitat designation is defined by the map or maps, as modified by any accompanying regulatory text, presented at the end of this document under Regulation Promulgation. We include more detailed information on the boundaries of the critical habitat designation in the preamble of this document. We will make the coordinates or plot points or both on which each map is based available to the public on

https://www.regulations.gov

at Docket No. FWS-R3-ES-2024-0144.

Final Critical Habitat Designation

We are designating approximately 599 river miles (rmi) (964 river kilometers (rkm)) in 15 units as critical habitat for rayed bean; approximately 801 rmi (1,289 rkm) in 11 units as critical habitat for sheepnose; approximately 2,425 rmi (3,902 rkm) in 38 units as critical habitat for snuffbox; and approximately 1,140 rmi (1,835 rkm) in 12 units as critical habitat for spectaclecase. In total, we are designating approximately 3,814 unique rmi (6,138 rkm) of critical habitat within 76 units across 17 States; many units overlap entirely or within some portion of the designated units for the mussel species that are the subject of this final rule. All units are considered to be occupied by the species—which are already listed as endangered species under the Act. No unoccupied units are being designated for any of the four species. All critical habitat units consist of the streambed up to the ordinary high-water mark, as defined at 33 CFR 328.3(c)(4) in the regulations that implement the Clean Water Act (33 U.S.C. 1251

et seq.

). Streambed ownership varies by State and by navigability of the stream. In general, the streambed up to the ordinary high-water mark is public waters of the State; however, there are instances where the streambed is owned by the adjacent landowners. When describing land ownership, below, we use adjacent landownership as a proxy for streambed ownership that is consistent across the ranges of these species. The critical habitat areas we describe below constitute our current best assessment of areas that meet the definition of critical habitat for all four species.

The 15 areas we designate as critical habitat for the rayed bean are: (1) Black River, (2) Pine River, (3) Belle River, (4) River Raisin, (5) Clinton River, (6) Fish Creek, (7) Swan Creek, (8) Blanchard River, (9) Allegheny River, (10) Middle Allegheny River, (11) French Creek, (12) Little Darby Creek, (13) Big Darby Creek, (14) Great Miami River, and (15) Tippecanoe River. Table 2 shows the critical habitat units, identifies the owners by type (Federal, State, local, or private) of land adjacent to each unit, and provides the approximate area of each unit. We use the four-letter species code for rayed bean (RABE) to name its critical habitat units. All units are considered occupied at the time of listing.

Table 2—Critical Habitat Units for Rayed Bean

[Length estimates reflect all land within critical habitat unit boundaries.]

Critical habitat unit or subunit name

Adjacent land ownership type

Size of unit

in river miles

(river kilometers)

RABE 1: Black River

State

Private

Total

7 (11)

25 (40)

32 (51)

RABE 2: Pine River

Private

Total

3 (5)

3 (5)

RABE 3: Belle River

Private

Total

8 (13)

8 (13)

RABE 4: River Raisin

Local

Private

Total

0.3 (0.5)

8 (13)

8 (13)

RABE 5: Clinton River

Local

Private

Total

1 (2)

7 (11)

8 (13)

RABE 6: Fish Creek

State

Private

Total

1 (2)

30 (48)

31 (50)

RABE 7: Swan Creek

Private

Total

4 (7)

4 (7)

RABE 8: Blanchard River

Local

Private

Total

1 (2)

27 (43)

28 (45)

RABE 9: Allegheny River

State

Shared: State & Local *

Local

Private

Total

12 (19)

0.1 (0.2)

2 (3)

68 (109)

82 (131)

RABE 10: Middle Allegheny River

Federal

Shared: Federal & State *

State

Local

Private

Total

23 (37)

3 (5)

13 (21)

4 (6)

133 (209)

176 (283)

RABE 11: French Creek

Federal

State

Local

Private

Total

13 (21)

3 (5)

1 (2)

83 (134)

100 (161)

RABE 12: Little Darby Creek

State

Private

Total

4 (7)

17 (28)

21 (35)

RABE 13: Big Darby Creek

State

Local

Private

Total

1 (2)

13 (21)

24 (39)

38 (61)

RABE 14: Great Miami River

Private

Total

11 (18)

11 (18)

RABE 15a: Tippecanoe River

Local

Private

Total

1 (2)

27 (43)

28 (45)

RABE 15b: Tippecanoe River

State

Private

Total

2 (3)

17 (27)

19 (31)

Total by Ownership Type

Federal

Shared: Federal & State *

State

Shared: State & Local *

Local

Private

Total

36 (58)

3 (5)

43 (69)

0.1 (0.2)

24 (39)

493 (793)

599 (964)

* Shared ownership corresponds to stream segments with different public ownership on opposite sides of the river.

Note:

Lengths may not sum due to rounding.

The 11 areas we designate as critical habitat for the sheepnose are: (1) Lower Chippewa River, (2) Kankakee River, (3) Meramec and Bourbeuse Rivers, (4) Middle Allegheny-Tionesta, (5) Upper Green River, (6) Tippecanoe River, (7) Walhonding River, (8) Lower Tennessee River, (9) Upper Clinch River, (10) Powell River, and (11) Big Sunflower River. Table 3 shows the critical habitat units, identifies the owners by type (Federal, State, local, or private) of land adjacent to each unit, and provides the approximate area of each unit. We use the four-letter species code for sheepnose (SHNO) to name its critical habitat units. All units are considered occupied at the time of listing.

Table 3—Critical Habitat Units for Sheepnose

[Length estimates reflect all land within critical habitat unit boundaries.]

Critical habitat unit name

Adjacent land ownership type(s)

Size of unit in river miles

(river kilometers)

SHNO 1: Lower Chippewa River

Federal

Shared: Federal & State *

State

Local

Private

Total

5 (8)

1 (2)

29 (47)

1 (2)

21 (34)

57 (92)

SHNO 2: Kankakee River

State

Local

Private

Total

18 (29)

10 (16)

23 (37)

51 (82)

SHNO 3: Meramec and Bourbeuse Rivers

State

Local

Private

Total

18 (29)

18 (29)

117 (188)

153 (246)

SHNO 4: Middle Allegheny-Tionesta

State

Private

Total

0.04 (0.06)

28 (45)

28 (45)

SHNO 5: Upper Green River

Federal

State

Local

Private

Total

27 (43)

7 (11)

1 (2)

122 (196)

157 (253)

SHNO 6: Tippecanoe River

State

Private

Total

9 (14)

75 (121)

84 (135)

SHNO 7: Walhonding River

State

Local

Private

Total

0.5 (0.8)

1 (2)

22 (35)

24 (38)

SHNO 8: Lower Tennessee River

Local

Private

Total

0.4 (0.6)

22 (35)

23 (36)

SHNO 9: Upper Clinch River

Federal

State

Private

Total

0.3 (0.5)

6 (10)

100 (161)

106 (171)

SHNO 10: Powell River

State

Private

Total

0.3 (0.5)

62 (100)

63 (101)

SHNO 11: Big Sunflower River

Federal

State

Private

Total

0.5 (0.8)

2 (3)

53 (86)

56 (90)

Total by Land Ownership Type

Federal

Shared: Federal & State *

State

Local

Private

Total

33 (53)

1 (2)

89 (143)

31 (50)

647 (1,041)

801 (1,289)

* Shared ownership corresponds to stream segments with different public ownership on opposite sides of the river.

Note:

Lengths may not sum due to rounding.

The 38 areas we designate as critical habitat for the snuffbox are: (1) Wolf River, (2) Embarrass River, (3) Little Wolf River, (4) Grand River (Michigan), (5) Clinton River, (6) Huron River, (7) Grand River (Ohio), (8) Allegheny River, (9) French Creek, (10) West Fork River, (11) Shenango River, (12) Middle Island Creek, (13) Little Kanawha River, (14) Kanawha River, (15) Olentangy River, (16) Little Darby Creek, (17) Big Darby Creek, (18) Stillwater River, (19) Tygarts Creek, (20) Kinniconick Creek, (21) Licking River, (22) Middle Fork Kentucky River, (23) Red Bird River, (24) Red River, (25) Green River, (26) Salamonie River, (27) Tippecanoe River, (28) Embarras River, (29) Rolling Fork Salt River, (30) Clinch River, (31) Powell River, (32) Paint Rock River, (33) Elk River, (34) Duck River, (35) St. Croix River, (36) Meramec River, (37) St. Francis River, and (38) Spring River. Table 4 shows the critical habitat units, identifies the owners by type (Federal, State, local, or private) of land adjacent to each unit, and provides the approximate area of each unit. We use the four-letter species code for snuffbox (SNBO) to name its critical habitat units. All units are considered occupied at the time of listing.

Table 4—Critical Habitat Units for Snuffbox Mussel

[Length estimates reflect all land within critical habitat unit boundaries.]

Critical habitat unit or subunit name

Adjacent land ownership type(s)

Size of unit in river miles

(river kilometers)

SNBO 1: Wolf River

Federal

State

Local

Private

Total

0.2 (0.3)

0.7 (1)

0.4 (0.7)

7 (11)

8 (13)

SNBO 2a: Embarrass River

Private

Total

11 (18)

11 (18)

SNBO 2b: Embarrass River

Private

Total

7 (11)

7 (11)

SNBO 3: Little Wolf River

Private

Total

12 (19)

12 (19)

SNBO 4: Grand River (Michigan)

State

Local

Private

Total

9 (14)

5 (8)

27 (43)

41 (65)

SNBO 5: Clinton River

Local

Private

Total

0.9 (1)

7 (12)

8 (13)

SNBO 6: Huron River

State

Local

Private

Total

7 (11)

2 (3)

7 (12)

16 (26)

SNBO 7: Grand River (Ohio)

Local

Private

Total

8 (12)

16 (25)

23 (37)

SNBO 8: Allegheny River

State

Local

Private

Total

6 (10)

0.2 (0.3)

29 (46)

35 (57)

SNBO 9a: French Creek

State

Private

Total

0.7 (1)

18 (29)

19 (30)

SNBO 9b: French Creek

Federal

State

Local

Private

Total

13 (21)

14 (23)

3 (4)

81 (131)

111 (179)

SNBO 10: West Fork River

Private

Total

22 (35)

22 (35)

SNBO 11: Shenango River

State

Local

Private

Total

0.7 (1)

0.5 (0.8)

26 (42)

28 (44)

SNBO 12: Middle Island Creek

State

Local

Private

Total

0.1 (0.2)

2 (3)

85 (137)

87 (140)

SNBO 13: Little Kanawha River

Federal

State

Local

Private

Total

0.5 (0.7)

17 (27)

0.1 (0.2)

183 (294)

200 (322)

SNBO 14: Kanawha River

State

Local

Private

Total

2 (3)

2 (3)

54 (87)

58 (93)

SNBO 15: Olentangy River

State

Private

Total

0.3 (0.4)

30 (48)

30 (48)

SNBO 16: Little Darby Creek

State

Local

Private

Total

4 (6)

0.004 (0.006)

24 (39)

28 (45)

SNBO 17: Big Darby Creek

State

Local

Private

Total

0.6 (0.9)

20 (32)

49 (78)

69 (111)

SNBO 18: Stillwater River

Local

Private

Total

0.6 (1)

11 (18)

12 (19)

SNBO 19: Tygarts Creek

State

Private

Total

1 (2)

88 (141)

89 (143)

SNBO 20: Kinniconick Creek

Private

Total

52 (84)

52 (84)

SNBO 21: Licking River

State

Local

Private

Total

15 (24)

3 (5)

221 (355)

239 (385)

SNBO 22: Middle Fork Kentucky River

Private

Total

13 (21)

13 (21)

SNBO 23: Red Bird River

Federal

Private

Total

3 (5)

57 (92)

60 (97)

SNBO 24: Red River

Federal

Shared: Federal & State *

State

Private

Total

17 (28)

0.8 (1)

0.5 (0.8)

12 (19)

31 (49)

SNBO 25: Green River

Federal

State

Local

Private

Total

27 (43)

7 (11)

2 (4)

121 (195)

157 (253)

SNBO 26: Salamonie River

Federal

Private

Total

9 (15)

3 (5)

12 (19)

SNBO 27a: Tippecanoe River

Local

Private

Total

1 (2)

27 (43)

28 (45)

SNBO 27b: Tippecanoe River

State

Private

Total

2 (3)

17 (27)

19 (31)

SNBO 28: Embarras River

State

Local

Private

Total

5 (8)

3 (5)

63 (101)

71 (114)

SNBO 29: Rolling Fork Salt River

Private

Total

95 (153)

95 (153)

SNBO 30: Clinch River

Federal

State

Local

Private

Total

0.3 (0.5)

9 (15)

0.4 (0.6)

160 (257)

170 (273)

SNBO 31: Powell River

State

Private

Total

0.3 (0.5)

66 (106)

66 (106)

SNBO 32: Paint Rock River

Shared: Federal & State *

State

Private

Total

0.3 (0.5)

49 (80)

3 (6)

53 (85)

SNBO 33: Elk River

Private

Total

27 (43)

27 (43)

SNBO 34: Duck River

State

Local

Private

Total

27 (43)

0.4 (0.6)

20 (32)

47 (76)

SNBO 35: St. Croix River

Federal

Shared: Federal & State *

State

Local

Private

Total

19 (31)

4 (6)

8 (13)

0.1 (0.2)

22 (35)

53 (85)

SNBO 36: Meramec River

State

Shared: State & Local *

Local

Private

Total

23 (37)

0.05 (0.09)

4 (6)

200 (321)

227 (365)

SNBO 37: St. Francis River

Federal

State

Private

Total

0.05 (0.08)

5 (8)

53 (85)

58 (93)

SNBO 38: Spring River

State

Private

Total

1 (2)

32 (51)

33 (53)

Total by Ownership Type

Federal

Shared: Federal & State *

State

Shared: State & Local *

Local

Private

Total

89 (143)

5 (8)

221 (356)

0.05 (0.08)

54 (87)

2,056 (3,309)

2,425 (3,902)

* Shared ownership corresponds to stream segments with different public ownership on opposite sides of the river.

Note:

Lengths may not sum due to rounding.

The 12 areas we designate as critical habitat for the spectaclecase are: (1) St. Croix River, (2) Mississippi River, (3) Meramec River, (4) Big River, (5) Gasconade River, (6) Big Piney River, (7) Ouachita River, (8) Tennessee River, (9) Clinch River, (10) Nolichucky River, (11) Green River, and (12) Kanawha River. Table 5, below, shows the critical habitat units, identifies the owners by type (Federal, State, local, or private) of land adjacent to each unit, and provides the approximate area of each unit. We use the four-letter species code for spectaclecase (SPCA) to name its critical habitat units. All units are considered occupied at the time of listing.

Table 5—Critical Habitat Units for Spectaclecase

[Length estimates reflect all land within critical habitat unit boundaries.]

Critical habitat unit or subunit name

Adjacent land ownership types

Size of unit in river miles

(river kilometers)

SPCA 1: Saint Croix

Federal

Shared: Federal & State *

State

Local

Private

Total

19 (31)

3 (5)

9 (14)

1 (2)

21 (34)

53 (86)

SPCA 2: Mississippi River

Federal

Shared: Federal & State *

Shared: Federal & Local *

State

Shared: State & Local *

Local

Private

Total

28 (45)

6 (10)

0.4 (0.6)

5 (8)

0.2 (0.3)

11 (18)

82 (132)

132 (212)

SPCA 3: Meramec River

State

Shared: State & Local *

Local

Private

Total

29 (47)

0.5 (0.8)

17 (27)

110 (177)

156 (251)

SPCA 4: Big River

Local

Private

Total

1 (2)

10 (16)

11 (18)

SPCA 5: Gasconade River

Federal

State

Private

Total

9 (14)

3 (5)

211 (340)

223 (359)

SPCA 6a: Big Piney River

Federal

Shared: Federal & State *

State

Private

Total

17 (27)

0.5 (0.8)

0.5 (0.8)

16 (26)

34 (55)

SPCA 6b: Big Piney River

Federal

Private

Total

14 (23)

5 (8)

19 (31)

SPCA 7: Ouachita River

Local

Private

Total

1 (2)

82 (132)

83 (134)

SPCA 8: Tennessee River

Federal

Shared: Federal & State *

State

Shared: State & Local *

Local

Private

Total

0.3 (0.5)

20 (32)

112 (180)

2 (3)

0.5 (0.8)

7 (11)

142 (229)

SPCA 9: Clinch River

State

Private

Total

9 (15)

148 (238)

157 (253)

SPCA 10: Nolichucky River

State

Private

Total

2 (4)

35 (56)

37 (60)

SPCA 11: Green River

Federal

State

Private

Total

26 (42)

5 (8)

46 (74)

77 (124)

SPCA 12: Kanawha River

Local

Private

Total

0.4 (0.6)

15 (24)

16 (25)

Total by Ownership Type

Federal

Shared: Federal & State *

Shared: Federal & Local *

State

Shared: State & Local *

Local

Private

Total

114 (183)

31 (50)

0.4 (0.6)

174 (280)

3 (5)

31 (50)

787 (1,267)

1,140 (1,835)

* Shared ownership corresponds to stream segments with different public ownership on opposite sides of the river.

Note:

Lengths may not sum due to rounding.

We present brief descriptions of all units, and reasons why they meet the definition of critical habitat, for the rayed bean, sheepnose, snuffbox, and spectaclecase mussels below.

I. Rayed Bean

All 15 units for rayed bean are considered occupied by the species at the time of listing and contain all of the physical or biological features essential to the species' conservation.

RABE 1: Black River

RABE 1 consists of approximately 32 rmi (51 rkm) of the Black River and Mill Creek in St. Clair County, Michigan. The Black River portion of the unit includes 8 rmi (13 rkm) in St. Clair County, Michigan, from the State Highway 136 Bridge (Beard Road Bridge) in Clyde Township downstream to the Wadhams Road Bridge in Kimball Township. This unit also includes 24 rmi (38 rkm) of Mill Creek in St. Clair County, Michigan, from its confluence with Thompson Drain northwest of Brockway Township downstream to its confluence with Black River at Ruby in Clyde Township, Michigan. The unit includes the river channel up to the ordinary high-water mark.

Approximately 21.5 percent (7 rmi (11 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State) ownership, and 78.5 percent (25 rmi (40 rkm)) are in private ownership. Adjacent State lands are owned or managed by the Michigan Department of Natural Resources. The unit partially overlaps with proposed critical habitat for the proposed endangered salamander mussel (

Simpsonaias ambigua

) (88 FR 57224, August 22, 2023).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to the amount of impervious surface and urbanization; and the presence of invasive species.

RABE 2: Pine River

RABE 2 consists of approximately 3 rmi (5 rkm) of the Pine River in St. Clair County, Michigan. This unit extends from the confluence of the Pine River and Rattle Run downstream to Newman Road in St. Clair Township (St. Clair County, Michigan). The unit includes the river channel up to the ordinary high-water mark.

All of the riparian lands adjacent to, but not included in, this unit are in private ownership.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to the amount of impervious surface and urbanization; and the presence of invasive species.

RABE 3: Belle River

RABE 3 consists of approximately 8 rmi (13 rkm) of the Belle River in St. Clair County, Michigan. This unit extends from the Westrick Road Bridge downstream to the King Road Bridge in China Township, in St. Clair County, Michigan. The unit includes the river channel up to the ordinary high-water mark.

All of the riparian lands adjacent to, but not included in, this unit are in private ownership.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to the amount of impervious surface and urbanization; and the presence of invasive species.

RABE 4: River Raisin

RABE 4 consists of approximately 8 rmi (13 rkm) of the River Raisin in Lenawee County, Michigan. This unit extends from the Crockett Highway Bridge in Palmyra Township downstream to the U.S. Route 223 Bridge (West Adrian Street) in the village of Blissfield, in Lenawee County, Michigan. The unit includes the river channel up to the ordinary high-water mark.

Approximately 3.2 percent (0.3 rmi (0.5 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (local) ownership, and 96.8

percent (8 rmi (13 rkm)) are in private ownership.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to the amount of impervious surface and urbanization; and the presence of invasive species.

RABE 5: Clinton River

RABE 5 consists of approximately 8 rmi (13 rkm) of the Clinton River in Oakland County, Michigan. This unit extends from downstream of the fish hatchery at Waterford Township downstream to Cass Lake east of the unincorporated community of Four Towns, in Oakland County, Michigan. The unit includes the river channel up to the ordinary high-water mark.

Approximately 11.0 percent (1 rmi (2 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (local) ownership, and 89.0 percent (7 rmi (11 rkm)) are in private ownership. The unit fully overlaps with designated critical habitat for the federally endangered snuffbox mussel and partially overlaps with proposed critical habitat for the proposed endangered salamander mussel (88 FR 57224; August 22, 2023).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminant; habitat degradation and loss due to the amount of impervious surface, urbanization, and the lack of canopy cover and vegetative cover in the riparian buffer; reduced connectivity due to barriers; and the presence of invasive species.

RABE 6: Fish Creek

RABE 6 consists of approximately 31 rmi (50 rkm) of Fish Creek in Steuben and DeKalb Counties, Indiana, and Williams County, Ohio. This unit extends from the Ohio Turnpike Interstate 80/Interstate 90 Bridge in Steuben County, Indiana, downstream to the confluence of Fish Creek with St. Joseph River north of the village of Edgerton in Williams County, Ohio. The unit includes the river channel up to the ordinary high-water mark.

Approximately 3.3 percent (1 rmi (2 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State) ownership, and 96.7 percent (30 rmi (48 rkm)) are in private ownership. Adjacent State lands are owned or managed by the Ohio Department of Natural Resources. The unit partially overlaps with designated critical habitat for the federally threatened rabbitsfoot (

Quadrula cylindrica cylindrica

) (see 50 CFR 17.95(f) and 80 FR 24692, April 30, 2015) and fully overlaps with proposed critical habitat for the proposed endangered salamander mussel (88 FR 57224, August 22, 2023).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; impacts to the hydrological regime; habitat degradation and loss due to sedimentation and stream channelization; and the presence of invasive species.

RABE 7: Swan Creek

RABE 7 consists of approximately 4 rmi (7 rkm) of Swan Creek in Lucas County, Ohio. This unit extends from the Monclova Road Bridge in the city of Maumee downstream to the Ohio Turnpike Interstate 80/Interstate 90 Bridge in the city of Maumee, in Lucas County, Ohio. The unit includes the river channel up to the ordinary high-water mark.

All of the riparian lands adjacent to, but not included in, this unit are in private ownership.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; impacts to the hydrological regime; habitat degradation and loss due to the amount of impervious surface and urbanization; and the presence of invasive species.

RABE 8: Blanchard River

RABE 8 consists of 28 rmi (45 rkm) of the Blanchard River in Hardin and Hancock Counties, Ohio. This unit extends from the County Road 183 Bridge in Jackson Township (Hardin County, Ohio) downstream to the State Route 568 Bridge (Carey Road Bridge) in the city of Findlay (Hancock County, Ohio). The unit includes the river channel up to the ordinary high-water mark.

Approximately 4.3 percent (1 rmi (2 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (local) ownership, and 95.7 percent (27 rmi (43 rkm)) are in private ownership.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to sedimentation and stream channelization; and the presence of invasive species.

RABE 9: Allegheny River

RABE 9 consists of approximately 82 rmi (131 rkm) of the Allegheny River, Honeoye Creek, Olean Creek, Oil Creek, and Oswayo Creek in Allegany and Cattaraugus Counties, New York, and McKean and Potter Counties, Pennsylvania. The Allegheny River portion of this unit includes approximately 47 rmi (76 rkm) of the Allegheny River from its confluence with Sartwell Creek near the unincorporated community of Burtville in McKean County, Pennsylvania, downstream to the Interstate 86 Bridge in the village of Allegany, in Cattaraugus County, New York. The Olean Creek portion of this unit includes approximately 8 rmi (14 rkm) of Olean Creek from its confluence with Oil Creek in the town of Hinsdale downstream to the confluence with Allegheny River in the city of Olean, in Cattaraugus County, New York. The Oil Creek portion of this unit includes approximately 7 rmi (11 rkm) of Oil Creek from the Interstate 86 Bridge near the Cattaraugus County/Allegany County line in New York downstream to its confluence with Olean Creek in the town of Hinsdale, in Cattaraugus County, New York. The Oswayo Creek portion of this unit includes approximately 12 rmi (19 rkm) of Oswayo Creek its confluence with Honeoye Creek in Potter County, Pennsylvania, downstream to its confluence with Allegheny River just west of the village of Portville in Cattaraugus County, New York). The Honeoye Creek portion of this unit includes approximately 7 rmi (11 rkm) of Honeoye Creek from the New York/Pennsylvania State Line in Allegany County, New York, and Potter County, Pennsylvania, downstream to its confluence with Oswayo Creek. The unit includes the river channel up to the ordinary high-water mark.

Approximately 17.2 percent (14 rmi (22 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State and local) ownership, and 82.8 percent (68 rmi (109 rkm)) are in private ownership. Adjacent State lands are owned or managed by the New York State Office of Parks, Recreation and Historic Preservation and the Pennsylvania Game Commission.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants and resource

extraction; reduced connectivity due to barriers; habitat degradation and loss due to urbanization, sedimentation, and stream channelization; and the presence of invasive species.

RABE 10: Middle Allegheny River

RABE 10 consists of 176 rmi (283 rkm) of the Allegheny River and Oil Creek in Armstrong, Butler, Clarion, Forest, Venango, Warren, and Westmoreland Counties, Pennsylvania. The Allegheny River portion of this unit extends approximately 171 rmi (275 rkm) from the Kinzua Dam in Warren County, Pennsylvania, downstream to the mouth of the Kiskiminetas River in Armstrong and Westmoreland Counties, Pennsylvania. The Oil Creek portion of this unit includes approximately 5 rmi (8 rkm) from the Oil Creek State Park Ice Control Dam in Venango County, Pennsylvania, downstream to Oil Creek's confluence with the Allegheny River in Oil City, Venango County, Pennsylvania. The unit includes the river channel up to the ordinary high-water mark.

Approximately 24.4 percent (43 rmi (74 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (Federal, State, and local) ownership, and 75.6 percent (133 rmi (209 rkm)) are in private ownership. Adjacent Federal lands are owned or managed by the U.S. Forest Service and the Service. Adjacent State lands are owned or managed by the Pennsylvania Bureau of Forestry and the Pennsylvania Game Commission. The unit partially overlaps with designated critical habitat for the federally threatened longsolid (

Fusconaia subrotunda

) (see 50 CFR 17.95(f) and 88 FR 14794, March 9, 2023), the federally threatened rabbitsfoot (see 50 CFR 17.95(f) and 80 FR 24692, April 30, 2015), the federally endangered sheepnose, and the federally endangered snuffbox, and proposed critical habitat for the proposed endangered salamander mussel (88 FR 57224, August 22, 2023).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; reduced connectivity due to barriers; habitat degradation and loss due to urbanization, sedimentation, and stream channelization; and the presence of invasive species.

RABE 11: French Creek

RABE 11 consists of 100 rmi (161 rkm) of French Creek, LeBoeuf Creek, Muddy Creek, and Cussewago Creek in Crawford, Erie, Mercer, and Venango Counties, Pennsylvania. The French Creek portion of this unit includes 77 rmi (124 rkm) of French Creek from the Union City Reservoir Dam northeast of Union City (Erie County, Pennsylvania) downstream to its confluence with the Allegheny River near the city of Franklin (Venango County, Pennsylvania). The LeBoeuf Creek portion of this unit includes 3 rmi (5 rkm) of LeBoeuf Creek from the State Highway 97 Bridge in Waterford Township downstream to its confluence with French Creek in LeBoeuf Township, in Erie County, Pennsylvania. The Muddy Creek portion of this unit includes 14 rmi (23 rkm) of Muddy Creek from Pennsylvania Highway 77 near the unincorporated community of Little Cooley downstream to its confluence with French Creek east of the borough of Cambridge Springs, in Crawford County, Pennsylvania. The Cussewago Creek portion of this unit includes 6 rmi (10 rkm) of Cussewago Creek from the Rogers Ferry Road Bridge in Hayfield Township downstream to its confluence with French Creek in the city of Meadville, in Crawford County, Pennsylvania. The unit includes the river channel up to the ordinary high-water mark.

Approximately 17.3 percent (17 rmi (27 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (Federal, State, and local) ownership, and 82.7 percent (83 rmi (134 rkm)) are in private ownership. Adjacent Federal lands are owned or managed by the Service. Adjacent State lands are owned or managed by the Pennsylvania Game Commission. The unit partially overlaps with designated critical habitat for the federally threatened longsolid (see 50 CFR 17.95(f) and 88 FR 14794, March 9, 2023), the federally threatened rabbitsfoot (see 50 CFR 17.95(f) and 80 FR 24692, April 30, 2015), the federally endangered sheepnose, and the federally endangered snuffbox mussel, and proposed critical habitat for the proposed endangered salamander mussel (88 FR 57224; August 22, 2023).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants and resource extraction; habitat degradation and loss due to urbanization, sedimentation, and stream channelization; the presence of invasive species; and the loss of riparian buffer zones.

RABE 12: Little Darby Creek

RABE 12 consists of 21 rmi (35 rkm) of Little Darby Creek in Madison and Union Counties, Ohio. This unit extends from the Ohio Highway 161 Bridge near the unincorporated community of Chuckery (Union County, Ohio) downstream to the U.S. Highway 40 Bridge near the village of West Jefferson (Madison County, Ohio). The unit includes the river channel up to the ordinary high-water mark.

Approximately 19.6 percent (4 rmi (7 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State) ownership, and 80.4 percent (17 rmi (28 rkm)) are in private ownership. Adjacent State lands are owned or managed by the Ohio Department of Natural Resources. The unit fully overlaps with designated critical habitat for the federally threatened rabbitsfoot (see 50 CFR 17.95(f) and 80 FR 24692, April 30, 2015) and the federally endangered snuffbox mussel.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to urbanization, sedimentation, and stream channelization; and the presence of invasive species.

RABE 13: Big Darby Creek

RABE 13 consists of 38 rmi (61 rkm) of Big Darby Creek in Franklin, Madison, and Union Counties, Ohio. This unit extends from the Highway 36 Bridge in the village of Milford Center (Union County, Ohio) downstream to the State Route 665 Bridge (London Groveport Road) by the unincorporated community of Darbydale (Franklin County, Ohio). The unit includes the river channel up to the ordinary high-water mark.

Approximately 36.8 percent (14 rmi (22 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State and local) ownership, and 63.2 percent (24 rmi (39 rkm)) are in private ownership. Big Darby Creek is a State Scenic River, and adjacent State lands are owned or managed by the Ohio Department of Natural Resources. The unit fully overlaps with designated critical habitat for the federally endangered snuffbox mussel.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to urbanization, sedimentation, and stream channelization; reduced connectivity due to a barrier; and the presence of invasive species.

RABE 14: Great Miami River

RABE 14 consists of approximately 11 rmi (18 rkm) of the Great Miami River in Logan and Shelby Counties, Ohio. This unit extends from the dam at Riverside Park in village of Quincy (Logan County, Ohio) downstream to the Route 47 Bridge (Riverside Drive) in city of Sidney (Shelby County, Ohio). The unit includes the river channel up to the ordinary high-water mark.

All of the riparian lands adjacent to, but not included in, this unit are in private ownership.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to urbanization, sedimentation, and stream channelization; reduced connectivity due to barriers; and the presence of invasive species.

RABE 15: Tippecanoe River

RABE 15 consists of 47 rmi (76 rkm) of the Tippecanoe River in Carroll, Pulaski, Tippecanoe, and White Counties, Indiana. This unit is composed of two subunits, and each subunit includes the river channel up to the ordinary high-water mark.

Subunit RABE 15a includes 28 rmi (45 rkm) of the Tippecanoe River from the State Highway 14 Bridge near the town of Winamac (Pulaski County, Indiana) downstream to the Lowes Bridge Road crossing in White County, Indiana.

Subunit RABE 15b includes 19 rmi (31 rkm) of the Tippecanoe River from the Oakdale Dam in Carroll County, Indiana, downstream to the confluence of the Tippecanoe River with the Wabash River northeast of the town of Battle Ground (Tippecanoe County, Indiana).

Approximately 6.6 percent (3 rmi (5 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State and local) ownership, and 93.4 percent (44 rmi (71 rkm)) are in private ownership. Adjacent State lands are owned or managed by the Indiana Department of Natural Resources. Both subunits partially overlap with designated critical habitat for the federally threatened rabbitsfoot (see 50 CFR 17.95(f) and 80 FR 24692, April 30, 2015), the federally threatened round hickorynut (see 50 CFR 17.95(f) and 88 FR 14794; March 9, 2023), the federally endangered sheepnose, and proposed critical habitat for the proposed endangered salamander mussel (88 FR 57224, August 22, 2023), and fully overlap with designated critical habitat for the federally endangered snuffbox mussel.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to urbanization, sedimentation, and stream channelization; reduced connectivity due to barriers; and the presence of invasive species.

II. Sheepnose

All 11 units for sheepnose are considered occupied by the species at the time of listing and contain all of the physical or biological features essential to the species' conservation.

SHNO 1: Lower Chippewa River

SHNO 1 consists of 57 rmi (92 rkm) of the lower Chippewa River in Buffalo, Dunn, Eau Claire, and Pepin Counties, Wisconsin. This unit extends from the confluence of the lower Chippewa River with the Eau Clair River (Eau Claire County, Wisconsin), downstream to its confluence with the Mississippi River (Buffalo/Pepin Counties, Wisconsin). The unit includes the river channel up to the ordinary high-water mark.

Approximately 63.0 percent (36 rmi (58 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (Federal, State, and local) ownership, and 37.0 percent (21 rmi (34 rkm)) are in private ownership. Adjacent Federal lands are owned or managed by the Service as part of the Upper Mississippi River National Wildlife Refuge, and adjacent State lands are owned or managed by the Wisconsin Department of Natural Resources. This unit partially overlaps with proposed critical habitat for the proposed endangered salamander mussel (88 FR 57224; August 22, 2023).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants, and reduced connectivity due to barriers.

SHNO 2: Kankakee River

SHNO 2 consists of 51 rmi (82 rkm) of the Kankakee River in Grundy, Kankakee, and Will Counties, Illinois. This unit extends from the confluence of the Kankakee River with West Creek (Kankakee County, Illinois) downstream to its confluence with the Illinois River (Grundy County, Illinois). The unit includes the river channel up to the ordinary high-water mark.

Approximately 54.9 percent (28 rmi (45 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State, and local) ownership, and 45.1 percent (23 rmi (37 rkm)) are in private ownership. Adjacent State lands are owned or managed by the Illinois Department of Natural Resources.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants and sedimentation, and in-stream gravel mining.

SHNO 3: Meramec and Bourbeuse Rivers

SHNO 3 consists of 153 rmi (246 rkm) of the Meramec and Bourbeuse Rivers in Franklin, Jefferson, and Saint Louis Counties, Missouri. This unit consists of 90 rmi (145 rkm) of the Meramec River from its confluence with Rye Creek (Franklin County, Missouri) downstream to its confluence with Mississippi River (Jefferson County, Missouri). SHNO 3 also includes 63 rmi (101 rkm) of the Bourbeuse River from its confluence with Little Creek downstream to its confluence with the Meramec River, in Franklin County, Missouri. The unit includes the river channel up to the ordinary high-water mark.

Approximately 23.7 percent (36 rmi (58 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State and local) ownership, and 76.3 percent (117 rmi (188 rkm)) are in private ownership. Adjacent State lands are owned or managed by the Missouri Department of Conservation and Missouri Department of Natural Resources. This unit partially overlaps with designated critical habitat for the federally endangered snuffbox, and the federally endangered spectaclecase.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; reduced connectivity due to barriers; the presence of invasive species; loss of riparian zones; and habitat degradation and loss due to urbanization.

SHNO 4: Middle Allegheny-Tionesta

SHNO 4 consists of 28 rmi (45 rkm)) of the Allegheny River in Forest and Venango Counties, Pennsylvania. This units extends from the confluence of the Allegheny River with Tionesta Creek (Forest County, Pennsylvania) downstream to its confluence with French Creek (Venango County, Pennsylvania). The unit includes the

river channel up to the ordinary high-water mark.

Approximately 0.14 percent (0.04 rmi (0.06 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State) ownership, and 99.86 percent (28 rmi (45 rkm)) are in private ownership. Adjacent State lands are owned or managed by the Pennsylvania Fish and Boat Commission. The unit fully overlaps with designated critical habitat for the federally threatened longsolid (see 50 CFR 17.95(f) and 88 FR 14794; March 9, 2023) and the federally endangered rayed bean, and partially overlaps with the designated critical habitat for the federally threatened rabbitsfoot (see 50 CFR 17.95(f) and 80 FR 24692, April 30, 2015).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants and resource extraction; reduced connectivity due to barriers; habitat degradation and loss due to urbanization, sedimentation, and stream channelization; and the presence of invasive species.

SHNO 5: Upper Green

SHNO 5 consists of 157 rmi (253 rkm) of the Green River in Butler, Edmonson, Green, Hart, Taylor, and Warren Counties, Kentucky. This unit extends from the confluence of the Green River with the Barren River (Taylor County, Kentucky) downstream to the Green River Dam (Butler County, Kentucky). The unit includes the river channel up to the ordinary high-water mark.

Approximately 22.5 percent (35 rmi (56 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (Federal, State, and local) ownership, and 77.5 percent (122 rmi (196 rkm)) are in private ownership. Adjacent Federal lands are owned or managed by the U.S. Army Corps of Engineers and the National Park Service, and adjacent State lands are owned or managed by the Kentucky Department of Agriculture and the Kentucky Division of Water—Wild Rivers Program. The unit partially overlaps with designated critical habitat for the federally endangered diamond darter (

Crystallaria cincotta

) (see 50 CFR 17.95(e) and 78 FR 52364, August 22, 2013), the federally threatened round hickorynut (see 50 CFR 17.95(f) and 88 FR 14794, March 9, 2023), the federally threatened rabbitsfoot (see 50 CFR 17.95(f) and 80 FR 24692, April 30, 2015), and the federally endangered spectaclecase, and the proposed critical habitat for the proposed endangered Kentucky creekshell (see 50 CFR 17.95(f) and 89 FR 76196, September 17, 2024), and fully overlaps with designated critical habitat for the federally threatened longsolid (see 50 CFR 17.95(f) and 88 FR 14794, March 9, 2023) and the federally endangered snuffbox.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of habitat and water quality from impoundments and associated cold water discharges; siltation and pollution due to improper timbering, sedimentation, and stream channelization; resource extraction; water withdrawals; and development.

SHNO 6: Tippecanoe River

SHNO 6 consists of 84 rmi (135 rkm) of the Tippecanoe River in Fulton, Marshall, Pulaski, Starke, and White Counties, Indiana. This unit extends from the confluence of the Tippecanoe River with Outlet Creek (Marshall County, Indiana) downstream to Lake Freeman (White County, Indiana). The unit includes the river channel up to the ordinary high-water mark.

Approximately 10.35 percent (9 rmi (14 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State) ownership, and 89.65 percent (75 rmi (121 rkm)) are in private ownership. Adjacent State lands are owned or managed by the Indiana Department of Natural Resources. The unit partially overlaps with designated critical habitat for the federally threatened rabbitsfoot (see 50 CFR 17.95(f) and 80 FR 24692, April 30, 2015), the federally endangered rayed bean, the federally threatened round hickorynut (see 50 CFR 17.95(f) and 88 FR 14794; March 9, 2023), and the federally endangered snuffbox mussel, and fully overlaps with the proposed critical habitat for the proposed endangered salamander mussel (88 FR 57224, August 22, 2023).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to urbanization, sedimentation, and stream channelization; reduced connectivity due to barriers; and the presence of invasive species.

SHNO 7: Walhonding River

SHNO 7 consists of 24 rmi (38 rkm) of the Walhonding River in Coshocton County, Ohio. This unit extends from the confluence of the Kokosing River and the Mohican River at the unincorporated community of Walhonding downstream to the confluence of the Walhonding River with the Tuscarawas River, in Coshocton County, Ohio. The unit includes the river channel up to the ordinary high-water mark.

Approximately 4.9 percent (1 rmi (2 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State and local) ownership, and 95.1 percent (22 rmi (36 rkm)) are in private ownership. Adjacent State lands are owned or managed primarily by the Ohio Department of Natural Resources. The unit partially overlaps with designated critical habitat for the federally threatened rabbitsfoot (see 50 CFR 17.95(f) and 80 FR 24692, April 30, 2015).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants, sedimentation, and stream channelization.

SHNO 8: Lower Tennessee River

SHNO 8 consists of 23 rmi (36 rkm) of the Tennessee River in Livingston, Marshall, and McCracken Counties, Kentucky. This unit extends from the Kentucky Dam (Marshall/Livingston Counties, Kentucky) downstream to the confluence of the lower Tennessee River with the Ohio River (McCracken County, Kentucky). The unit includes the river channel up to the ordinary high-water mark.

Approximately 1.8 percent (0.4 rmi (0.6 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (local) ownership, and 98.2 percent (22 rmi (35 rkm)) are in private ownership. The unit fully overlaps with designated critical habitat for the federally threatened rabbitsfoot (see 50 CFR 17.95(f) and 80 FR 24692, April 30, 2015).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to in-stream gravel mining; degradation and loss of habitat due to dredging; reduced connectivity due to barriers; and the presence of invasive species.

SHNO 9: Upper Clinch River

SHNO 9 consists of 106 rmi (171 rkm) of the Clinch River in Russell, Scott, and Wise Counties, Virginia, and Hancock County, Tennessee. This unit extends from the confluence of the upper Clinch River with Thompson Creek (Russell County, Virginia) downstream to its

confluence with Big Creek (Hancock County, Tennessee). The unit includes the river channel up to the ordinary high-water mark.

Approximately 6.1 percent (6 rmi (10 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (Federal and State) ownership, and 93.9 percent (100 rmi (161 rkm)) are in private ownership. Adjacent Federal lands are owned or managed by the U.S. Forest Service, and adjacent State lands are owned or managed by the Tennessee Wildlife Resources Agency or the Virginia Department of Conservation and Recreation. The unit fully overlaps with designated critical habitat for the federally endangered Cumberlandian combshell (

Epioblasma brevidens

), the federally endangered oyster mussel (

Epioblasma capsaeformis

), the federally endangered purple bean (

Villosa perpurpurea

), and the federally endangered rough rabbitsfoot (

Quadrula cylindrica strigillata

) (see 50 CFR 17.95(f) and 69 FR 53136, August 31, 2004); the federally endangered fluted kidneyshell, and the federally endangered slabside pearlymussel (see 50 CFR 17.95(f) and 78 FR 59956, September 26, 2013); the federally threatened longsolid (see 50 CFR 17.95(f) and 88 FR 14794, March 9, 2023); the federally threatened slender chub (

Erimystax cahni

) (see 50 CFR 17.95(e) and 42 FR 45526, September 9, 1977); the federally endangered snuffbox; and the federally endangered spectaclecase; and partially overlaps with the designated critical habitat for the federally threatened yellowfin madtom (

Noturus flavipinnis

) (see 50 CFR 17.95(e) and 42 FR 45526, September 9, 1977), and the proposed critical habitat for the federally threatened sickle darter (

Percina williamsi

) (88 FR 4128; January 24, 2023).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of habitat and water quality from downstream impoundment, mining discharges, siltation, contaminants, resource extraction, and water withdrawals; urbanization; and the presence of invasive species.

SHNO 10: Powell River

SHNO 10 consists of 63 rmi (101 rkm) of the Powell River in Lee County, Virginia, and Claiborne and Hancock County, Tennessee. This unit extends from the confluence of the Powell River with the Little Yellow Branch (Lee County, Virginia) downstream to Highway 25E (Dixie Highway E) (Claiborne County, Tennessee). The unit includes the river channel up to the ordinary high-water mark.

Approximately 0.5 percent (0.3 rmi (0.5 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State) ownership, and 99.5 percent (62 rmi (100 rkm)) are in private ownership. Adjacent State lands are owned or managed by the Tennessee Department of Environment and Conservation or the Virginia Department of Conservation and Recreation. This unit fully overlaps with designated critical habitat for the federally endangered Cumberlandian combshell, federally endangered oyster mussel, federally endangered purple bean, and federally endangered rough rabbitsfoot (see 50 CFR 17.95(f) and 69 FR 53136, August 31, 2004); the federally endangered fluted kidneyshell, and the federally endangered slabside pearlymussel (see 50 CFR 17.95(f) and 78 FR 59956, September 26, 2013); the federally threatened slender chub and federally threatened yellowfin madtom (see 50 CFR 17.95(e) and 42 FR 45526, September 9, 1977); and the federally endangered snuffbox.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants, urbanization, resource extraction, sedimentation, stream channelization; reduced connectivity due to barriers; the presence of invasive species; and changes to the hydrological regime.

SHNO 11: Big Sunflower River

SHNO 11 consists of 56 rmi (90 rkm) of the Big Sunflower River in Bolivar and Sunflower Counties, Mississippi. This unit begins where Merigold-Drew Road crosses the Big Sunflower River (Bolivar County, Mississippi) and extends downstream to the confluence of the Big Sunflower River with the Quiver River (Sunflower County, Mississippi). The unit includes the river channel up to the ordinary high-water mark.

Approximately 4.1 percent (2 rmi (4 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (Federal and State) ownership, and 95.9 percent (54 rmi (86 rkm)) are in private ownership. Adjacent Federal lands are owned or managed by the NRCS. Adjacent State lands are owned or managed by the Mississippi Secretary of State and Mississippi Forestry Commission. The unit partially overlaps with designated critical habitat for the federally threatened rabbitsfoot (see 50 CFR 17.95(f) and 80 FR 24692, April 30, 2015).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants and sedimentation; degradation and loss of habitat due to dredging and stream channelization; and changes to the hydrological regime.

III. Snuffbox

All 38 units for snuffbox are considered occupied by the species at the time of listing and contain all of the physical or biological features essential to the species' conservation.

SNBO 1: Wolf River

SNBO 1 consists of 8 rmi (13 rkm) of the Wolf River in Shawano County, Wisconsin. This unit extends from the Shawano Dam downstream to the County Road CCC Bridge near the town of Waukechon, in Shawano County, Wisconsin. The unit includes the river channel up to the ordinary high-water mark.

Approximately 17.0 percent (1 rmi (2 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (Federal, State, and local) ownership, and 83.0 percent (7 rmi (11 rkm)) are in private ownership. Adjacent Federal land is owned or managed by the Bureau of Land Management. Adjacent State lands are owned or managed by the Wisconsin Department of Natural Resources.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to urbanization; reduced connectivity due to barriers; impacts to the hydrological regime; and the presence of invasive species.

SNBO 2: Embarrass River

SNBO 2 consists of 18 rmi (29 rkm) of the Embarrass River, South Branch Embarrass River, and North Branch Embarrass River in Shawano County, Wisconsin. This unit is composed of two subunits, and each subunit includes the river channel up to the ordinary high-water mark.

Subunit SNBO 2a includes approximately 11 rmi (18 rkm) of the South Branch Embarrass River in Shewano County, Wisconsin, from Spaulding Street (County Road M) in Tigerton downstream to its confluence with Embarrass River in the town of Grant.

Subunit SNBO 2b includes approximately 7 rmi (11 rkm) of the Embarrass River and the North Fork Embarrass River in Shawano County, Wisconsin. The Embarrass River includes approximately 5 rmi (8 rkm) of the Embarrass River and extends from the Caroline Dam in the town of Grant downstream to its confluence with North Branch Embarrass River, in Shawano County, Wisconsin. The North Branch Embarrass River portion of this unit includes approximately 2 rmi (3 rkm) of North Branch Embarrass from the dam in the unincorporated community of Leopolis downstream to its confluence with Embarrass River, in Shawano County, Wisconsin.

All of the riparian lands adjacent to, but not included in, this unit are in private ownership.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to urbanization; reduced connectivity due to barriers; impacts to the hydrological regime; and the presence of invasive species.

SNBO 3: Little Wolf River

SNBO 3 consists of 12 rmi (19 rkm) of the Little Wolf River in Waupaca County, Wisconsin. This unit extends from the Manawa Mill Pond Dam in the city of Manawa downstream to the Highway X Bridge in the town of Mukwa, in Waupaca County, Wisconsin. The unit includes the river channel up to the ordinary high-water mark.

All of the riparian lands adjacent to, but not included in, this unit are in private ownership.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to urbanization; reduced connectivity due to barriers; impacts to the hydrological regime; and the presence of invasive species.

SNBO 4: Grand River (Michigan)

SNBO 4 consists of 41 rmi (65 rkm) of the Grand River and the Flat River in Ionia and Kent Counties, Michigan. The Grand River portion of this unit includes 40 rmi (64 rkm) of the Grand River and extends from the Webber Dam upstream of the village of Lyons (Ionia County, Michigan) downstream to its confluence with Thornapple River in the unincorporated community of Ada (Kent County, Michigan). The Flat River portion of this unit includes 0.5 rmi (0.8 rkm) of the Flat River from West State Highway 21 in the city of Lowell downstream to its confluence with Grand River in the city of Lowell, in Kent County, Michigan. The unit includes the river channel up to the ordinary high-water mark.

Approximately 33.5 percent (14 rmi (22 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State and local) ownership, and 66.5 percent (27 rmi (43 rkm)) are in private ownership. Adjacent State lands are owned or managed by the Michigan Department of Natural Resources.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to urbanization; reduced connectivity due to barriers; and the presence of invasive species.

SNBO 5: Clinton River

SNBO 5 consists of 8 rmi (13 rkm) of the Clinton River in Oakland County, Michigan. This unit extends from downstream of the fish hatchery at Waterford Township downstream to Cass Lake east of the unincorporated community of Four Towns, in Oakland County, Michigan. The unit includes the river channel up to the ordinary high-water mark.

Approximately 11.0 percent (0.9 rmi (1 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (local) ownership, and 89.0 percent (7 rmi (12 rkm)) are in private ownership. The unit fully overlaps with designated critical habitat for the federally endangered rayed bean and partially overlaps with proposed critical habitat for the proposed endangered salamander mussel (88 FR 57224; August 22, 2023).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; habitat degradation and loss due to the amount of impervious surface, urbanization, and the lack of canopy cover and vegetative cover in the riparian buffer; reduced connectivity due to barriers; and the presence of invasive species.

SNBO 6: Huron River

SNBO 6 consists of 16 rmi (26 rkm) of the Huron River in Livingston County, Michigan. This unit extends from Strawberry Lake downstream to the Kent Lake Dam, in Livingston County, Michigan. The unit includes the river channel up to the ordinary high-water mark.

Approximately 55.5 percent (9 rmi (14 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State and local) ownership, and 44.5 percent (7 rmi (12 rkm)) are in private ownership. Adjacent State lands are owned or managed by the Michigan Department of Natural Resources.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants; reduced connectivity due to barriers; and the presence of invasive species.

SNBO 7: Grand River (Ohio)

SNBO 7 consists of 23 rmi (37 rkm) of the Grand River in Ashtabula and Lake Counties, Ohio. This unit extends from the Harpersfield Dam in the unincorporated community of Harpersfield (Ashtabula County, Ohio) downstream to the Norfolk and Western Railroad Trestle (Lake County, Ohio). The unit includes the river channel up to the ordinary high-water mark.

Approximately 33.1 percent (8 rmi (12 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (local) ownership, and 66.9 percent (16 rmi (25 rkm)) are in private ownership. This unit fully overlaps with designated critical habitat for the federally threatened round hickorynut (see 50 CFR 17.95(f) and 88 FR 14794, March 9, 2023).

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of habitat and water quality from impoundments, domestic and industrial pollution due to human development, resource extraction, water withdrawals, and wastewater treatment plants; and the presence of invasive species.

SNBO 8: Allegheny River

SNBO 8 consists of 35 rmi (57 rkm) of the Allegheny River in Venango County, Pennsylvania. This unit extends from the Allegheny River's confluence with French Creek near city of Franklin downstream to Interstate 80 near the borough of Emlenton, in Venango County, Pennsylvania. The unit includes the river channel up to the ordinary high-water mark.

Approximately 18.6 percent (6 rmi (11 rkm)) of the riparian lands adjacent to, but not included in, this unit are in public (State and local) ownership, and 81.4 percent (29 rmi (46 rkm)) are in private ownership. Adjacent State lands

are owned or managed by the Pennsylvania Bureau of Forestry and the Pennsylvania Fish and Boat Commission. The unit fully overlaps with designated critical habitat for the federally threatened longsolid (see 50 CFR 17.95(f) and 88 FR 14794; March 9, 2023), the federally threatened rabbitsfoot (see 50 CFR 17.95(f) and 80 FR 24692, April 30, 2015), and the federally endangered rayed bean, and partially overlaps with the critical habitat designation for the federally endangered sheepnose.

The features essential to the conservation of this species may require special management considerations or protection to reduce the following threats: degradation of water quality due to contaminants, sedimentation, stream channelization, and resource extraction; reduced connectivity due to barriers (

e.g.,

locks and dams); channelization; and the presence of invasive species.

SNBO 9: French Creek

SNBO 9 consists of 130 rmi (209 rkm) of French Creek, West Branch French Creek, LeBoeuf Creek, Cussewago Creek, Woodcock Creek, Muddy Creek, and Conneaut Outlet in Erie, Crawford, Lebanon, Mercer, and Venango Counties, Pennsylvania. SNBO 9 includes two subunits, and each subunit includes the river channel up to the ordinary high-water mark.

Subunit SNBO 9a includes 19 rmi (30 rkm) of the West Branch French Creek portion in Erie County, Pennsylvania from the Aston Road Bridge in Greenfield Township just west of the New York/Pennsylvania State line downstream to its confluence with French Creek in Wattsburg.

Subunit SNBO 9b includes 111 rmi (179 rkm) of the French Creek, LeBoeuf Creek, Cussewago Creek, Woodcock Creek, Muddy Creek, and Conneaut Outlet in Erie, Crawford, Mercer, and Venango Counties, Pennsylvania. The French Creek portion of this unit includes 75 rmi (121 rk

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