# Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Narrow-Headed Gartersnake

> Briefs, arguments, decisions, and more.

URL: https://www.frixlaw.com/law-library/documents/fr%3A2021-20962

## Record

- **Collection:** Federal Register
- **Document type:** Rule
- **Published:** October 21, 2021
- **Citation:** 86 FR 58474

## Text

DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R2-ES-2020-0011; FF09E21000 FXES1111090FEDR 223]
RIN 1018-BD96
Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Narrow-Headed Gartersnake

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Final rule.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), designate critical habitat for the narrow-headed gartersnake (
Thamnophis rufipunctatus
) under the Endangered Species Act of 1973 (Act), as amended. In total, 23,785 acres (9,625 hectares) in Greenlee, Apache, Yavapai, Gila, and Coconino Counties, Arizona, and Grant, Hidalgo, and Catron Counties, New Mexico, fall within the boundaries of the critical habitat designation for the narrow-headed gartersnake. This rule extends the Act's protections to the narrow-headed gartersnake's designated critical habitat.

DATES:

This rule is effective November 22, 2021.

ADDRESSES:

This final rule is available on the internet at
http://www.regulations.gov
. Comments and materials we received, as well as supporting documentation we used in preparing this rule, are available for public inspection at
http://www.regulations.gov
at Docket No. FWS-R2-ES-2020-0011.

The coordinates or plot points or both from which the maps are generated are included in the decision file for this critical habitat designation and are available at
http://www.regulations.gov
at Docket No. FWS-R2-ES-2020-0011 or on the Service's website at
https://www.fws.gov/southwest/es/arizona/
. Additional supporting information that we developed for this critical habitat designation will be available on the Service's website set out above and at
http://www.regulations.gov
.

FOR FURTHER INFORMATION CONTACT:

Jeff Humphrey, Field Supervisor, U.S. Fish and Wildlife Service, Arizona Ecological Services Field Office, Fish and Wildlife Office, 9828 North 31st Ave. #C3, Phoenix, AZ 85051-2517; telephone 602-242-0210. Persons who use a telecommunications device for the deaf (TDD) may call the Federal Relay Service at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish a rule.
Under the Act, if we determine that a species is an endangered or threatened species, we must designate critical habitat to the maximum extent prudent and determinable. On July 8, 2014, we published a final rule to list the narrow-headed gartersnake as a threatened species (79 FR 38678). Designations of critical habitat can be completed only by issuing a rule.

What this document does.
This rule designates critical habitat for the narrow-headed gartersnake of approximately 23,785 acres (9,625 hectares) in Greenlee, Apache, Yavapai, Gila, and Coconino Counties, Arizona, and Grant, Hidalgo, and Catron Counties, New Mexico.

The basis for our action.
Under section 4(a)(3) of the Act, if we determine that any species is an endangered or threatened species, we must, to the maximum extent prudent and determinable, designate critical habitat. 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. The Secretary may exclude an area from critical habitat if she determines that the benefits of such exclusion outweigh the benefits of specifying such areas as part of critical habitat, unless she determines, based on the best scientific data available, that the failure to designate such area as critical habitat will result in the extinction 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.

The critical habitat we are designating in this rule, consisting of eight units comprising approximately 447 stream miles (719 kilometers) within a maximum 326-foot (100-meter) lateral extent of the active stream channel, in an area of 23,784 acres (9,625 hectares) for the narrow-headed gartersnake, constitutes our current best assessment of the areas that meet the definition of critical habitat for the species.

Peer review and public comment.
During the proposed rule stage, we sought the expert opinions of eight appropriate specialists. We received responses from three specialists, which informed our determination. Information we received from peer review is incorporated into this final rule. We also considered all comments and information we received from the public during the comment period.

Previous Federal Actions

Please refer to the final listing rule (79 FR 38678; July 8, 2014), the original proposed critical habitat rule (78 FR 41550; July 10, 2013), and the revised proposed critical habitat rule (85 FR 23608; April 28, 2020) for the narrow-headed gartersnake for a detailed description of previous Federal actions concerning this species. Those rules included the northern Mexican gartersnake (
Thamnophis eques megalops
), but we designated critical habitat for the northern Mexican gartersnake in an earlier, separate final rule (80 FR 22518; April 28, 2021). This rule designates critical habitat only for the narrow-headed gartersnake.

Supporting Documents

In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we stated that a draft analysis document under the National Environmental Policy Act (NEPA; 42 U.S.C. 4321
et seq.
) for the designation of critical habitat would be completed. We have now finalized an environmental assessment with a finding of no significant impact under NEPA. The environmental assessment and finding of no significant impact are available at
http://www.regulations.gov
at Docket No. FWS-R2-ES-2020-0011 and from the Arizona Ecological Services Field Office at
https://www.fws.gov/southwest/es/arizona/
. See Required Determinations, below, for a discussion of our NEPA obligations for this designation.

No changes were made to our economic analysis after considering public comment on the draft document. The final updated economic analysis document (IEc 2021, entire) is available at
http://www.regulations.gov at
Docket No. FWS-R2-ES-2020-0011.

Summary of Changes From the Proposed Rule

We reviewed the comments related to critical habitat for the narrow-headed gartersnake (see Summary of Comments and Recommendations, below), completed our analysis of areas

considered for exclusion under section 4(b)(2) of the Act (16 U.S.C. 1531
et seq.
), reviewed our analysis of the physical or biological features (PBFs) essential to the long-term conservation of the narrow-headed gartersnake, and finalized the economic analysis of the designation. This final rule incorporates changes from our 2020 revised proposed critical habitat rule (85 FR 23608; April 28, 2020) based on the comments that we received, and have responded to in this document, and considers efforts to conserve the narrow-headed gartersnake.

As a result, our final designation of critical habitat reflects the following changes from the April 28, 2020, revised proposed rule (85 FR 23608):

(1) We revised unit areas based on comments we received regarding areas that did or did not contain the PBFs essential to the conservation of the species. These changes resulted in a net increase of 5,081 acres (ac) (2,056 hectares (ha)) of critical habitat. Critical habitat units were extended laterally to capture areas needed for brumation, a period of dormancy during the winter. All areas added to this final critical habitat designation were proposed as critical habitat for the narrow-headed gartersnake in the 2013 original proposed critical habitat rule (78 FR 41550; July 10, 2013) (see
Summary of Essential Physical or Biological Features
).

(2) We modified PBFs 1(B), 1(C), 1(D), and 3 for the narrow-headed gartersnake as identified below under Physical or Biological Features Essential to the Conservation of the Species.

(3) We excluded approximately 508 ac (206 ha) from portions of units for the narrow-headed gartersnake, as identified below in Table 2 (Areas excluded from critical habitat designation by critical habitat unit for the narrow-headed gartersnake).

(4) We corrected several errors in unit descriptions.

Summary of Comments and Recommendations

We requested written comments from the public on the original proposed critical habitat rule (78 FR 41550; July 10, 2013) and on the revised proposed critical habitat rule (85 FR 23608; April 28, 2020) for the narrow-headed gartersnake. The comment period for the original proposed critical habitat rule opened on July 10 and closed on September 9, 2013; the comment period for the revised proposed critical habitat rule opened on April 28 and closed on June 29, 2020.

For the original proposed critical habitat rule (78 FR 41550; July 10, 2013), we contacted appropriate Federal, State, and Tribal governments; local agencies; scientific organizations; and other interested parties and invited them to comment on the proposed critical habitat designation. For the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we again contacted all interested parties, including appropriate Federal and State agencies, Tribal governments, scientific experts and organizations, and other interested parties, and invited them to submit written comments on the revised proposal. In the April 28, 2020, revised proposed rule, we stated that any comments we received in response to the July 10, 2013, proposed rule need not be resubmitted as they would be fully considered in this final rule. Newspaper notices inviting general public comments were published throughout the range of the proposed critical habitat designation for both the original and revised proposed rules.

During the comment period on the original proposed critical habitat rule (78 FR 41550; July 10, 2013), we received approximately 30 written comment letters on the proposed critical habitat designation. During the comment period on the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we received an additional 40 comment letters on the revised proposed critical habitat designation or the draft economic analysis (IEc 2019, entire). We also received one additional request for exclusion of an area that was not identified in the revised proposed rule. We reviewed each exclusion request and whether the requester provided information or a reasoned rationale to initiate an analysis or support an exclusion (see Policy Regarding Implementation of Section 4(b)(2) of the Endangered Species Act (81 FR 7226; February 11, 2016)). All substantive information provided during both comment periods has either been incorporated directly into this final determination or is addressed in our responses below.

We also note that we no longer use primary constituent elements (PCEs) to identify areas as critical habitat. We eliminated PCEs due to redundancy with the physical or biological features (PBFs). This change in terminology is in accordance with a February 11, 2016 (81 FR 7414), rule to implement changes to the regulations for designating critical habitat. In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we used the comments we had received and additional information to revise: (1) The PBFs that are essential to the conservation of the species and which may require special management considerations or protection under the Act; (2) the criteria used to define the areas occupied at the time of listing for the species; and (3) the criteria used to identify critical habitat boundaries. We then applied the revised PBFs and identification criteria for the species, along with additional information we received regarding where these PBFs exist on the landscape to determine the geographic extent of each critical habitat unit. We received comments on the original proposed critical habitat rule (78 FR 41550; July 10, 2013) that referred to PCEs, and our responses to those comments below correlate with the respective PBFs from the revised proposed critical habitat rule (85 FR 23608; April 28, 2020).

Peer Review

In accordance with our peer review policy published on July 1, 1994 (59 FR 34270), and our August 22, 2016, memorandum updating and clarifying the role of peer review actions under the Act, we solicited expert opinion on the original proposed critical habitat rule (78 FR 41550; July 10, 2013) from eight knowledgeable individuals with scientific expertise that includes familiarity with the narrow-headed gartersnake and its habitat, biological needs, and threats. We received responses from three of the peer reviewers. In 2020, during the public comment period for the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we received comments from one of the peer reviewers regarding our revised proposed rule. We address these peer reviewer comments in this final rule as appropriate.

This rule designates critical habitat only for the narrow-headed gartersnake; therefore, in this rule, we limit our discussion of the peer reviewer and public comments we received to those concerning the narrow-headed gartersnake. We reviewed all the comments we received from the peer reviewers for substantive issues and new information regarding the narrow-headed gartersnake and its habitat use and needs. The peer reviewers provided additional information, clarifications, and suggestions to improve the designation. Our revised proposed critical habitat rule (85 FR 23608; April 28, 2020) was developed in part to address some of the concerns and information raised by the peer reviewers in 2013. The additional details and information we received from or that were raised by the peer reviewers have been incorporated into this final rule, as appropriate. Substantive comments we

received from peer reviewers as well as Federal, State, Tribal, and local governments, nongovernmental organizations, and the public are summarized below.

Comment 1:
One peer reviewer commented that nonnative fishes of the Centrarchidae and Ictaluridae families characterized by the term “spiny-rayed fishes” are not the only nonnative fishes that are detrimental to native fishes that are the prey for the gartersnake. They stated that the red shiner in the Cyprinidae family, nonnative mosquitofish in the Poeciliidae family, and nonnative trouts in the Salmonidae family all negatively impact native fishes as well. A second peer reviewer also commented that brown trout (
Salmo trutta
) are a harmful nonnative and would impact the PBFs related to lack of nonnative species in several subunits.

Our Response:
In determining the PBFs for the gartersnake, we intended to identify those species of nonnative fish that were both considered highly predatory on gartersnakes and also highly competitive with gartersnakes in terms of common prey resources. The nonnative fish species we view as most harmful to gartersnake populations include bass (
Micropterus
sp.), flathead catfish (
Pylodictis
sp.), channel catfish (
Ictalurus
sp.), sunfish (Centrarchidae), bullheads (
Ameiurus
sp.), bluegill (
Lepomis
sp.), crappie (
Pomoxis
sp.), and brown trout. While other species may negatively impact native fishes, we highlighted the nonnative fish species that pose the greatest threat to narrow-headed gartersnakes.

Comment 2:
One peer reviewer stated that our application of the “adverse modification” standard to fish renovation efforts is flawed because we can salvage gartersnakes prior to stream renovations and release them after a native fish prey base has been reestablished.

Our Response:
For the public and section 7 practitioners to understand the types of actions considered to have potential effects to designated critical habitat, we generally identify those types of actions that could potentially result in adverse modification of designated critical habitat. The actual effects of a proposed action on designated critical habitat are dependent on many factors related to both the action being proposed and the project area. Conservation measures can be evaluated against specific attributes of the proposed action at the time of consultation for their suitability and potential implementation. We agree that salvaging gartersnakes prior to stream renovations and then releasing them after a native fish prey base has been reestablished could be a conservation recommendation identified during section 7 consultation to address effects of such a proposed action that includes fish renovation efforts.

Comment 3:
One peer reviewer stated that no areas should be excluded from the critical habitat designation based on existing habitat conservation plans because we cannot enforce implementation of conservation plans.

Our Response:
Section 4(b)(2) of the Act (16 U.S.C. 1533(b)(2)) states that we shall designate and make revisions to critical habitat on the basis of the best available scientific data after taking into consideration the economic impact, national security impact, and any other relevant impact of specifying any particular area as critical habitat. The Act provides that we may exclude an area from critical habitat if we determine that the benefits of such exclusion outweigh the benefits of specifying such area as part of the critical habitat, unless we determine, based on the best scientific data available, that the failure to designate such area as critical habitat will result in the extinction of the species. Under our Policy Regarding Implementation of Section 4(b)(2) of the Endangered Species Act (81 FR 7226; February 11, 2016), when conducting this analysis we consider a number of factors including whether there are permitted conservation plans covering the species in the area such as habitat conservation plans, safe harbor agreements, or candidate conservation agreements with assurances, or whether there are non-permitted conservation agreements and partnerships that would be encouraged by designation of, or exclusion from, critical habitat. Under the policy, we analyze habitat conservation plans when weighing whether the benefits of exclusion outweigh the benefits of including these areas in the critical habitat designation, and our analysis includes looking at whether the permittee is properly implementing the plan and is expected to continue doing so. We have conducted a weighing analysis to determine if the benefits of exclusion outweigh the benefits of including these areas, and we have used our discretion to determine if the existing habitat conservation plans are sufficient to conserve the species (see discussion under Consideration of Impacts under Section 4(b)(2) of the Act, below).

Comment 4:
One peer reviewer commented that it would be helpful to have a rating system for the PBFs about prey bases consisting of native fishes and an absence of nonnative fishes, to show a gradient among sites.

Our Response:
For recovery implementation purposes, we see value in understanding and tracking the status of the PBFs related to prey base and absence of nonnative aquatic predators, such as nonnative fishes. However, in terms of species composition or relative abundance, we do not currently have information on what the threshold of each nonnative aquatic predator, or combination of such predators, is to be considered detrimental to the narrow-headed gartersnake. These thresholds would also vary depending on the condition of other PBFs, including organic and inorganic structural features in a stream.

Comment 5:
One peer reviewer commented on several PBFs that are incorrectly applied to several subunits for the narrow-headed gartersnake, including PBF 3 in the Campbell Blue Subunit, West Fork Gila River Subunit, the lower 2 miles of Iron Creek Subunit, and Little Creek Subunit, and PBF 4 in the lower 2 miles of Iron Creek Subunit, Little Creek Subunit, and South Fork Negrito Creek.

Our Response:
While we did not include descriptions of PBFs for each subunit in this document, we used the information provided by the peer reviewer in our reevaluation of occupancy in the revised proposed critical habitat rule (85 FR 23608; April 28, 2020).

Comment 6:
One peer reviewer commented that Willow Creek should be a subunit for the narrow-headed gartersnake because there is a museum record from 1989 or 1990 and there are adequate PBFs. Because the site was formerly suitable, it is likely to become recolonized.

Our Response:
In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we reviewed gartersnake occupancy to determine that a stream or stream reach was occupied by the narrow-headed gartersnake at the time of listing if it is within the historical range of the species, contains all PBFs for the species (although the PBFs concerning prey availability and presence of nonnative, aquatic predators are often in degraded condition), and has a last known record of occupancy between 1998 and 2019 (see Occupancy Records, 85 FR 23608, p. 23617-23619) (see Criteria Used To Identify Critical Habitat). Willow Creek does not have a record for the narrow-headed gartersnake that meets this occupancy definition, so it is not included in this final critical habitat designation for the species.

Comment 7:
One peer reviewer commented that we should add the mainstem of the Negrito reach from the confluence of the north and south fork Negrito Creeks to its confluence with the Tularosa River reach.

Our Response:
In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we reviewed gartersnake occupancy to determine that a stream or stream reach was occupied by the narrow-headed gartersnake at the time of listing if it is within the historical range of the species, contains all PBFs for the species (although the PBFs concerning prey availability and presence of nonnative, aquatic predators are often in degraded condition), and has a last known record of occupancy between 1998 and 2019 (see Occupancy Records, 85 FR 23608, p. 23617-23619) (see Criteria Used To Identify Critical Habitat). The mainstem of Negrito Creek meets this definition for the narrow-headed gartersnake and is included in this final critical habitat designation for the species.

Federal Agency Comments

Comment 8:
The U.S. Forest Service (USFS) commented that the term “spatially intermittent flow” used in PCE 1 of the original proposed critical habitat rule (78 FR 41550; July 10, 2013) is ambiguous because spacing between sections of flowing water can vary greatly and may not meet the biological needs of the gartersnake or its prey base.

Our Response:
In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020) and this rule, we define perennial, intermittent, and ephemeral as related to stream flow included in PBF 1 for the narrow-headed gartersnake and clarify the spectrum of stream flow regimes that provide stream habitat for the species based on scientifically accepted stream flow definitions (Levick
et al.
2008, p. 6; Stromberg
et al.
2009, p. 330) (see “Stream Flow” in 85 FR 23608, April 28, 2020, p. 23613; see also Physical or Biological Features Essential to the Conservation of the Species, below).

Comment 9:
USFS requested clarification of what level of water pollutants are “low enough not to affect recruitment” for PBF 1(C) for narrow-headed gartersnake in the revised proposed critical habitat rule (85 FR 23608; April 28, 2020).

Our Response:
We do not have specific data related to water pollutants that are “at levels low enough such that recruitment of narrow-headed gartersnakes is not inhibited” (85 FR 23608, April 28, 2020, p. 23648). Therefore, in this rule, we have amended this PBF to read as follows: “Water quality that meets or exceeds applicable State surface water quality standards” (see Physical or Biological Features Essential to the Conservation of the Species, below). Although water quality is not identified as a threat to the narrow-headed gartersnake, it is a threat to its prey base. Water quality that is absent of pollutants or has low levels of pollutants is needed to support the fish prey base for the narrow-headed gartersnake. State water quality standards identify levels of pollutants required to maintain communities of organisms that have a taxa richness, species composition, and functional organization that includes the fish prey base of the narrow-headed gartersnake.

Comment 10:
In response to the original proposed critical habitat rule (78 FR 41550; July 10, 2013), a Federal agency stated that we should make it clear that when the 600-foot (ft) (182-meter (m)) width of critical habitat falls outside the stream channel, such as when channels are constricted by narrow canyon walls, critical habitat does not include upland areas that would not be used by the narrow-headed gartersnake.

Our Response:
In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020) for the narrow-headed gartersnake, we defined the lateral extent of critical habitat to include terrestrial features within 89 ft (27 m) of the active channel of a stream that provide thermoregulation, shelter sites, and protection from predators. This lateral extent includes some portions of narrow canyon walls and limits upland areas beyond narrow canyon walls. This lateral distance was based on the greatest average distance narrow-headed gartersnakes moved from the water during the wet season at two different sites on the Tularosa River in New Mexico over a 3-year study with a sample size of 69 individuals (Jennings and Christman 2012, p. 12) (see “Terrestrial Space Along Streams,” 85 FR 23608, April 28, 2020, pp. 23614-23616).

Subsequently, we received two comments on the revised proposed critical habitat rule (85 FR 23608; April 28, 2020) that a distance of 89 ft (27 m) did not capture known brumation sites on canyon walls used by narrow-headed gartersnakes in Oak Creek Canyon in Arizona (see
Comment 43,
below). As explained in our response to comment 43 below, we increased the lateral extent of critical habitat up to 328 ft (100 m) in areas with steep canyon walls to more accurately capture areas used by the narrow-headed gartersnake for brumation. This lateral extent also limits upland areas beyond narrow canyon walls, and we conclude that the changes that we made in this rule address all comments on this issue.

Comment 11:
In response to the original proposed critical habitat rule (78 FR 41550; July 10, 2013), USFS commented that the gartersnake has strong fidelity for brumation or natal sites.

Our Response:
Although we have information that the narrow-headed gartersnake uses brumation sites, we are not aware of any literature supporting a conclusion that the species has strong fidelity for these brumation sites. In this designation, we include some areas that capture the PBFs of brumation sites that have been documented in telemetry studies conducted that are described in the revised proposed critical habitat rule (85 FR 23608, April 28, 2020—see “Terrestrial Space Along Streams” on pp. 85 FR 23614-23616).

Comment 12:
In response to the original proposed critical habitat rule (78 FR 41550; July 10, 2013), several Federal entities commented that various areas in the proposal do not currently contain the PBFs for narrow-headed gartersnakes. USFS further stated that it would be more realistic if we limited critical habitat to the areas that had the PBFs, if the PBFs are clearly defined and determinable.

Our Response:
For the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we reevaluated all streams to determine which stream reaches contain PBFs. The revised proposed critical habitat rule and this rule do not include stream reaches where we determined that water flow became completely ephemeral along an otherwise perennial or spatially intermittent stream, hydrologic processes needed to maintain streams could not be recovered, nonnative aquatic predators outnumbered native prey species, or streams were outside the elevation range for the narrow-headed gartersnake. The revised proposed critical habitat rule (85 FR 23608; April 28, 2020) and this rule include areas that were occupied at the time of listing and contain at least one of the PBFs. We acknowledge that in some locations, the PBFs concerning prey availability and presence of nonnative aquatic predators are often in degraded condition and may require special management (see Changes to Criteria Used to Identify Critical Habitat in 85 FR 23608, April 28, 2020, pp. 85 FR 23617-23623; and see Regulation Promulgation, below).

Comment 13:
In response to the original proposed critical habitat rule (78 FR 41550; July 10, 2013), several Federal agencies provided lists of

specific areas included in proposed critical habitat that do not have stream flow requirements defined in PBF 1(A) to support the narrow-headed gartersnake or its corresponding prey species identified in PBF 3. These agencies identified reaches that lacked PBF 1(A) in some areas along the following streams included in the 2013 proposed critical habitat rule for the narrow-headed gartersnake: Diamond Creek, Little Creek, and Turkey Creek in the Upper Gila River Subbasin; Eagle Creek in the Middle Gila River Subbasin; Dry Blue Creek, San Francisco River, and South Fork Negrito Creek in the San Francisco River Subbasin; and Canyon Creek and Carrizo Creek in the Upper Salt River Subbasin. These areas included stream reaches where water flow became completely ephemeral along an otherwise perennial or spatially intermittent stream, and many included the origin of streams, some of which were outside of the known elevation range of the species.

Our Response:
In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we did not include stream reaches where water flow becomes completely ephemeral along an otherwise perennial or spatially intermittent stream, and we incorporated related information received from USFS and others regarding stream flow. We incorporated stream flow information received from USFS for Diamond Creek and Gilita Creek in the Upper Gila River Subbasin Unit for narrow-headed gartersnake. Based on information from USFS and others related to lack of stream flow along Diamond Creek and Gilita Creek, designated critical habitat for the narrow-headed gartersnake along Diamond Creek ends 0.26 miles (mi) (0.4 kilometers (km)) upstream from Star Canyon, and critical habitat along Gilita Creek ends upstream of Willow Creek. The rule set that we applied in the 2020 revised proposed rule limited critical habitat to the known elevation range of the species and limited stream length by dispersal distance from confirmed gartersnake locations dated 1998 or later. When applied, these two factors of the rule set removed all other areas that the commenting Federal agencies identified as not having stream flow requirements for the narrow-headed gartersnake.

Comment 14:
In response to the original proposed critical habitat rule (78 FR 41550; July 10, 2013), USFS stated that narrow-headed gartersnake critical habitat in high montane meadows and stream origins in ponderosa pine and mixed conifer forests does not have potential to develop shoreline habitat as it is defined in PBF 1(C): Shoreline habitat with adequate structural complexity and appropriate amounts of shrub- and sapling-sized plants.

Our Response:
The PBFs in the revised proposed critical habitat rule (85 FR 23608; April 28, 2020) and this rule do not include the term “shoreline habitat” or the components that were included in shoreline habitat in the 2013 proposed rule. Instead, PBFs 1(B) and 1(D) focus on components that are found throughout all habitat types used by the narrow-headed gartersnake, including organic and natural inorganic structural features important to the narrow-headed gartersnake that fall within the stream channel and within terrestrial habitat that is up to 328 ft (100 m) from the active stream channel.

Comment 15:
USFS stated that many areas included in critical habitat in the original proposed critical habitat rule (78 FR 41550; July 10, 2013) do not have PBF 4: An absence of nonnative fish species of the families Centrarchidae and Ictaluridae, bullfrogs, and/or crayfish. USFS also stated that much of proposed critical habitat may not have the capacity to ever become recolonized by the narrow-headed gartersnake due to the current and likely future conditions of these nonnative invasive species. In response to the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), USFS further commented that it will be difficult if not impossible for USFS to attain this PBF on its lands that it manages because nonnative species are managed by the State and not by USFS.

Our Response:
The revised proposed critical habitat rule (85 FR 23608; April 28, 2020) and this final rule include areas that were occupied at the time of listing, but areas that contain nonnative aquatic predators are often in degraded condition and require special management. While recognizing USFS concerns, these areas have the capacity to be managed to improve the condition of the PBFs for the narrow-headed gartersnake through cooperative efforts between State wildlife agencies and USFS, and these types of efforts have already successfully been undertaken by USFS and State wildlife agencies within the range of the narrow-headed gartersnake.

Comment 16:
In response to the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), USFS stated that we did not provide much explanation for what might constitute special management considerations that may be needed in critical habitat, so it is not clear what types of management are likely to result in improved PBFs. USFS commented that there should be some recognition of the potential value of restorative actions that often have short-term adverse effects but are designed to result in beneficial effects (
e.g.,
channel restoration, prescribed fire, riparian vegetation improvements, etc.).

Our Response:
In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we stated that we were not changing any of the special management considerations from the 2013 original proposed critical habitat rule for the narrow-headed gartersnake (see Special Management Considerations or Protection in 85 FR 23608, April 28, 2020, p. 23624). However, the 2013 original proposed critical habitat rule did not include recognition of the potential value of restorative actions that often have short-term adverse effects but are designed to result in beneficial effects (see
Special Management Considerations or Protection
in 78 FR 41550, July 10, 2013, pp. 41555-41556). To address this comment and the information lacking in the 2013 original proposed critical habitat rule, we have added this information to the discussion of special management considerations in this final rule.

Comment 17:
In response to the original proposed critical habitat rule (78 FR 41550; July 10, 2013), USFS stated that proposed critical habitat for the narrow-headed gartersnake included areas outside of the known elevation range and areas that do not have records of the species, including portions of Diamond Creek, Gilita Creek, and Iron Creek in the Upper Gila River Subbasin.

Our Response:
In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we included the elevation range of narrow-headed gartersnake as a PBF essential to the conservation of the species and did not include areas in the proposed critical habitat designation outside of this elevation range.

Comment 18:
In response to the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), USFS stated that East Fork Black River, Bear Wallow Creek, and Fish Creek were not considered occupied by narrow-headed gartersnake in the original proposed critical habitat rule (78 FR 41550; July 10, 2013), and that we did not provide information to support these additions in the 2020 revised proposed critical habitat rule. USFS questioned the validity of the Arizona Game and Fish Department (AGFD) record for narrow-headed gartersnake in Fish Creek and further stated that Fish Creek was

heavily impacted by the 2011 Wallow Fire. USFS recommended removing East Fork Black River, Bear Wallow Creek, and Fish Creek from the final designation.

Our Response:
In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we reviewed gartersnake occupancy to determine that a stream or stream reach was occupied at the time of listing for the narrow-headed gartersnake if it is within the historical range of the species, contains PBFs for the species (although the PBFs concerning prey availability and presence of nonnative aquatic predators are often in degraded condition), and has a last known record of occupancy between 1998 and 2019 (see Occupancy Records, 85 FR 23608, p. 23617-23619) (see Criteria Used To Identify Critical Habitat). During this review, we became aware of additional records for areas we did not include in the 2013 proposed rule, and so we included them in our occupancy determination. While we did not discuss individual gartersnake records that contribute to occupancy in the 2013 proposed rule or the 2020 revised proposed rule, we have these records in our files. AGFD provided and verified records of narrow-headed gartersnakes in the East Fork Black River, Bear Wallow Creek, and Fish Creek (Arizona Game and Fish Department 2013, entire; Ryan 2020, pers. comm.). While the 2011 Wallow Fire significantly reduced native fish abundance in Fish Creek, native fish have since recolonized the stream (Nowak
et al.
2017, Table 3). For these reasons, we included these areas in this final designation.

Comment 19:
In response to the original proposed critical habitat rule (78 FR 41550; July 10, 2013), USFS stated that proposed critical habitat will affect numerous livestock grazing allotments on the Tonto National Forest. In addition, another Federal agency stated concerns about current and potential future management of public lands within proposed designated critical habitat areas, including grazing and off-highway vehicle (OHV) use. There is a grazing permit renewal under review that would allow for grazing October through January within the Palmerita Ranch allotment on riparian and upland areas. The agency also stated that there is a special recreational permit issued for an annual 3-day OHV poker run event, which would occur partially on navigable washes on Federal lands.

Our Response:
With respect to livestock grazing and OHV use in areas of critical habitat, Federal agencies that authorize, carry out, or fund actions that may affect listed species or designated critical habitat are required to consult with us to ensure the action is not likely to jeopardize listed species or destroy or adversely modify designated critical habitat. This consultation requirement under section 7 of the Act is not a prohibition of Federal agency actions; rather, it is a means by which they may ensure that their actions proceed in a manner that avoids jeopardy or adverse modification. Even in areas absent designated critical habitat, if the Federal agency action may affect a listed species, consultation is still required to ensure the action is not likely to jeopardize the species. Because the areas designated as critical habitat are occupied and consultation will be required to meet the jeopardy standard, the impact of the critical habitat designation should be minimal and administrative in nature.

Comment 20:
In response to the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), USFS stated that maintenance of adequate base flow in Eagle Creek is impacted by State water law and rights and outside of the purview of USFS. USFS expressed concern that Federal agencies may be impacted by the Act's section 7 reasonable and prudent measures that are not implementable.

Our Response:
We understand that maintenance of adequate base flow in streams is impacted by State water law and rights that are outside of the purview of USFS. Under section 7 of the Act when evaluating the effects on critical habitat, we consider impacts on base flow from ongoing State water management operations within the designated units that are not within the agencies' discretion to modify to be part of the baseline of an effects analysis. Service policy states that section 7 consultation should result in reasonable and prudent measures that minimize the impacts of incidental take to the extent reasonable and prudent. They should be developed in coordination with the action agency and applicant, in any, to ensure that the measures are reasonable, that they cause only minor changes to the project, and that they are within the legal authority and jurisdiction of the agency or applicant to carry out. Therefore, they must be implementable.

Comment 21:
In response to the original proposed critical habitat rule (78 FR 41550; July 10, 2013), USFS requested we define disturbance thresholds for actions “that would significantly increase sediment deposition or scouring within the stream channel” such as vegetation treatments, prescribed fire, and wildfire suppression. USFS also requested we include language addressing the scope, scale, and duration of actions “that would alter water chemistry beyond the tolerance limits of a gartersnake prey base” and actions “that would remove, diminish, or significantly alter the structural complexity of key natural structural habitat features in and adjacent to critical habitat.” USFS stated that these actions are extremely broad in scope and do not differentiate short-term impacts from true long-term, more permanent impacts that could result in adverse modification.

Our Response:
The purpose of the designation of critical habitat to identify those areas critical to the conservation of the species. For the public and section 7 practitioners to understand the types of actions considered to have potential effects on designated critical habitat, we generally identify those types of actions that could potentially result in adverse modification of designated critical habitat. The actual effects of a proposed action on designated critical habitat are dependent on many factors related to both the action being proposed and the project area. Therefore, we cannot determine and include thresholds for adverse modification in this rule. The appropriate process for that determination is the Act's section 7 process, during which specific factors within the proposed action and conditions within the project area can be evaluated.

Comment 22:
In response to the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), USFS commented that “[a]ctions and structures that would physically block movement of gartersnakes and their prey species” should not include a discussion of predatory species, because the presence of nonnative aquatic predatory species in a waterbody reduces population viability, which is considered under actions included in those “that would directly or indirectly result in the introduction, spread, or augmentation of predatory nonnative species in gartersnake habitat.”

Our Response:
Including this language with regard to nonnative aquatic predatory species within the description of actions and structures that would block the movements of gartersnakes and their prey species, as well as within the description of actions that would result in the introduction, spread, and augmentation of predatory nonnative species, is important to clarify two different types of effects that result from similar actions. The presence of such nonnative aquatic predatory species can both act as a barrier to movement and reduce habitat

quality due to presence of nonnative aquatic predatory species.

Comment 23:
In response to both the original proposed critical habitat rule (78 FR 41550; July 10, 2013) and the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), USFS and others stated that we need to provide a reasonable, rational, and non-arbitrary timeframe for restocking of streams treated with piscicides, as the application of a standard that would determine adverse modification if the prey base was affected as described for 7 or more days would in many cases preclude the application of piscicides to restore listed or at-risk aquatic species, forsaking their recovery for gartersnakes.

Our Response:
The purpose of the designation of critical habitat is not to evaluate every potential project or action that could adversely affect or modify designated critical habitat, but rather to identify those areas critical to the conservation of the narrow-headed gartersnake. For the public and section 7 practitioners to understand the types of actions considered to have potential effects to designated critical habitat, we generally identify those types of actions that could potentially result in adverse modification of designated critical habitat. The actual effects of a proposed action of designated critical habitat are dependent on many factors related to both the action being proposed and the project area. Therefore, we cannot determine and include overall thresholds for adverse modification in this rule. The appropriate process for that determination is during the Act's section 7 process, during which specific factors within the proposed action and conditions within the project area can be evaluated.

Comment 24:
The U.S. Small Business Administration and other commenters stated that we should consider the full scope of economic impacts to small entities and conduct a thorough Regulatory Flexibility Act analysis for critical habitat rules.

Our Response:
Under the Regulatory Flexibility Act (RFA; 5 U.S.C. 601
et seq.
), as amended by the Small Business Regulatory Enforcement Fairness Act of 1996 (SBREFA; 5 U.S.C. 801
et seq.
), Federal agencies are required to evaluate the potential incremental impacts of a rulemaking only on directly regulated entities. The regulatory mechanism through which critical habitat protections are realized is section 7 of the Act, which requires Federal agencies, in consultation with the Service, to ensure that any action authorized, funded, or carried out by the agency is not likely to adversely modify critical habitat. Therefore, only Federal action agencies are directly subject to the specific regulatory requirement (avoiding destruction and adverse modification) imposed by critical habitat designation. Under these circumstances, it is our position that only Federal action agencies will be directly regulated by this designation. Therefore, because Federal agencies are not small entities, we can certify that this rule will not have a significant economic impact on a substantial number of small entities (see Required Determinations, below). Thus, no regulatory flexibility analysis is required.

Comment 25:
The U.S. Small Business Administration commented that we should continue to engage with stakeholders early in the process and consider public comments.

Our Response:
Stakeholder engagement is important to balancing the long-term conservation of sensitive species and their habitats with the interests of stakeholders and the needs of the public. For our original proposed critical habitat rule (78 FR 41550; July 10, 2013) and revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we conducted outreach to relevant Federal, State, and local municipalities and stakeholders, and published public news releases to alert the public to the proposals and request public comments. Specifically, in the proposed rules, we solicited information from the public regarding potential exclusions of areas based on management plans or other conservation efforts including partnerships, as well as other information related to the species and potential impacts of designating critical habitat. This final rule outlines our consideration of public comments we received on both the original and revised proposed rules.

State Comments

Comment 26:
Arizona Game and Fish Department (AGFD) commented that while they recognize the intent of our use of the term “predatory sportfish,” it is important to point out that all sportfish are predatory, as are all of our native fishes (
i.e.,
they all prey on other organisms) and all interactions with sportfish are not negative. Further, not all sportfish or native species eat snakes.

Our Response:
In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we used the term “predatory sportfish” to explain how we delineated critical habitat: We identified and removed stream reaches where stocking or management of predatory sportfish is a priority and is conducted on a regular basis. In this rule, we have removed the term “predatory sportfish” and replaced it with “nonnative fish species of the families Centrarchidae and Ictaluridae,” so that it is consistent with the description of species used in the PBF related to nonnative aquatic predators.

Comment 27:
In response to our original proposed critical habitat rule (78 FR 41550; July 10, 2013), New Mexico Department of Game and Fish (NMDGF) commented that the narrow-headed gartersnake is known both historically and recently from all three of its properties within or adjacent to the Upper Gila River Subbasin Unit. These properties include the Red Rock Wildlife Management Area, which is a public fishing and recreation area; the Bill Evans Fishing Area, which is a public fishing site; and the Heart Bar Wildlife Area, which is a public fishing and recreation area. NMDGF also noted that the proposal includes its Glenwood State Fish Hatchery within the narrow-headed gartersnake San Francisco River Subbasin Unit.

Our Response:
In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we reviewed narrow-headed gartersnake occupancy to determine that a stream or stream reach was occupied at the time of listing for the narrow-headed gartersnake if it is within the historical range of the species, contains PBFs for the species (although the PBFs concerning prey availability and presence of nonnative aquatic predators are often in degraded condition), and has a last known record of occupancy between 1998 and 2019 (see Occupancy Records, 85 FR 23608, p. 23617-23619) (see Criteria Used To Identify Critical Habitat). As a result of our review of occupancy and implementation of our rule set for stream length, we have added Red Rock Wildlife Management Area, Bill Evans Fish Area, and Heart Bar Wildlife Area to the description of the Upper Gila River Subbasin Unit in this final critical habitat designation for the narrow-headed gartersnake.

Comment 28:
AGFD stated that the revised proposed critical habitat rule (85 FR 23608; April 28, 2020) is adequate for recovery of the narrow-headed gartersnake and that there are some areas that were occupied historically but from which the species has been extirpated. AGFD will continue the recovery efforts of reintroducing narrow-headed gartersnakes back into historically occupied habitats to contribute to recovery, regardless of their current occupied status or their critical habitat designation.

Our Response:
We appreciate the AGFD's partnership in the conservation and recovery of the narrow-headed

gartersnake. We only consider unoccupied areas to be essential where a critical habitat designation limited to geographical areas occupied at the time of listing by the species would be inadequate to ensure the conservation of the species. In addition, for an unoccupied area to be considered essential, we must determine that there is a reasonable certainty both that the area will contribute to the conservation of the species and that the area contains one or more of the PBFs essential to the conservation of the species. At this point in time, we do not know what areas within the species' historical range will contribute to the conservation of the species.

Comment 29:
Both AGFD and NMDGF stated concerns with the
Application of the “Adverse Modification” Standard
discussion in the revised proposed critical habitat rule (85 FR 23608, April 28, 2020, pp. 23633-23634). AGFD pointed out that in the same discussion in the original proposed critical habitat rule (78 FR 41550, July 10, 2013, pp. 41576-41577), we discuss activities “that may affect critical habitat, when carried out, funded, or authorized by a Federal agency [and that] should result in section 7 consultation,” but in the 2020 revised proposed critical habitat rule, we discuss the same activities but change the “may affect critical habitat” to “are likely to destroy or adversely modify critical habitat.” AGFD recommended that in the final rule we use the same language in this discussion that we used in the 2013 original proposed critical habitat rule. AGFD also expressed concern that the 2020 revised proposed critical habitat rule essentially says that the effect has already been determined that any of these activities will destroy or adversely modify critical habitat.

Our Response:
The change in wording as it applies to the
Application of the “Adverse Modification” Standard
in the 2020 revised proposed critical habitat rule (85 FR 23608, April 28, 2020) was a response to correct an error in phrasing from the original proposed critical habitat rule (78 FR 41550, July 10, 2013). In this rule's
Application of the “Adverse Modification” Standard
discussion, below, we include actions that could cause adverse effects to critical habitat, and not necessarily cause adverse modification to critical habitat, so that the public and section 7 practitioners can understand the types of actions we consider to have potential effects to designated critical habitat. The actual effects of a proposed action on designated critical habitat are dependent on many factors related to both the action being proposed and the project area. Therefore, we cannot determine and include thresholds for adverse modification in this rule. The appropriate process for that determination is the Act's section 7 process, during which specific factors within the proposed action and conditions within the project area can be evaluated.

Comment 30:
Both AGFD and NMDGF stated concerns with some activities included in the analysis of the “adverse modification” standard because the activities are valuable to the restoration and recovery of native species even if they have temporary impacts to critical habitat. AGFD and NMDGF expressed concern about the time threshold we included in the
Application of the “Adverse Modification” Standard
discussion to determine that actions that would deliberately remove, diminish, or significantly alter the native or nonnative, soft-rayed fish component of the prey base within occupied habitat for a period of 7 days or longer would reach an adverse modification determination. AGFD further explained that stream renovation projects are needed to ensure that a healthy native fish community exists and that gartersnakes will also thrive. Chemical renovations can take longer than 7 days for the chemicals to dissipate to levels that are safe for native fish, or multiple treatments may need to be conducted to be effective. NMDGF requested removing fish barriers, water diversion, fish habitat restoration, and chemical treatments from the
Application of the “Adverse Modification” Standard
discussion in the final rule.

Our Response:
In this rule's
Application of the “Adverse Modification” Standard
discussion, below, we acknowledge that some conservation actions will have short-term adverse effects but will ultimately result in long-term benefits to gartersnake critical habitat. The actual effects of a proposed action of designated critical habitat are dependent on many factors related to both the action being proposed and the project area. The appropriate process for that determination is the Act's section 7 process, during which specific factors within the proposed action and conditions within the project area can be evaluated. We understand that there are no clear data to suggest that narrow-headed gartersnakes must feed within 7 days of their last meal. As stated above, we also agree that it is not possible to determine and include thresholds for adverse modification in this rule. Therefore, in this rule, we removed the time threshold that commenters interpreted to limit fish removal to a 7-day window.

Comment 31:
NMDGF requested exclusion for the Glenwood State Fish Hatchery in the Whitewater Creek Subunit of the San Francisco River Subbasin Unit for the narrow-headed gartersnake because there are no records of the species within the hatchery boundary and Whitewater Creek is not perennial at the hatchery. NMDGF further explains that the Service's Memorandum for the Intra-Service Section 7 Endangered Species Act Consultation for the Proposed Operation and Maintenance of Hatchery Facilities NM F-66 Project concurred with a “no effect” determination for the narrow-headed gartersnake because the snake is not currently present.

Our Response:
In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we reviewed narrow-headed gartersnake occupancy to determine that a stream or stream reach was occupied at the time of listing for narrow-headed gartersnake if it is within the historical range of the species, contains PBFs for the species (although the PBFs concerning prey availability and presence of nonnative aquatic predators are often in degraded condition), and has a last known record of occupancy between 1998 and 2019 (see Occupancy Records, 85 FR 23608, p. 23617-23619) (see Criteria Used To Identify Critical Habitat). The segment of Whitewater Creek included in the critical habitat designation for the narrow-headed gartersnake meets this definition.

In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020) and this rule, we also define perennial, intermittent, and ephemeral as related to stream flow included in PBF 1 for the narrow-headed gartersnake and clarify the spectrum of stream flow regimes that provide stream habitat for the species based on scientifically accepted stream flow definitions (Levick
et al.
2008, p. 6; Stromberg
et al.
2009, p. 330) (see “Stream Flow” in 85 FR 23608, April 28, 2020, p. 23613; see also Physical or Biological Features Essential to the Conservation of the Species, below). Although Whitewater Creek is ephemeral at the Glenwood State Fish Hatchery, it is perennial upstream of the hatchery and downstream at its confluence with the San Francisco River, so the entire stream segment meets our definition of critical habitat.

Under section 7 of the Act, Federal agencies are required to consult with the Service to ensure that the actions they carry out, fund, or authorize are not

likely to jeopardize the continued existence of the species, or destroy or adversely modify critical habitat. For a jeopardy or “take” analysis, we analyze effects to a species if the species is present in the action area during the time of the action. For an adverse modification analysis, we analyze effects to critical habitat if critical habitat for a species is present in the action area. Therefore, defining where a species is occupied at the time of listing for critical habitat designation is not synonymous with a determination that an area is currently occupied for purposes of a jeopardy analysis under section 7 of the Act or a “take” analysis under section 10 of the Act. Those determinations depend on the best available information at the time of the analysis, and the likely effects and likelihood of take depend on the action under consideration.

While the Glenwood State Fish Hatchery along Whitewater Creek meets our definition of critical habitat, consideration of possible exclusions from critical habitat are in our discretion and generally follow our Policy Regarding Implementation of Section 4(b)(2) of the Endangered Species Act (81 FR 7226; February 11, 2016). With respect to NMDGF's request to exclude the Glenwood State Fish Hatchery along Whitewater Creek, we are not excluding the area from this final rule. See Consideration of Impacts under Section 4(b)(2) of the Act,
Private or Other Non-Federal Conservation Plans or Agreements and Partnerships, in General,
below.

Comment 32:
New Mexico Department of Agriculture (NMDA) expressed support for excluding private lands owned by Freeport-McMoRan within the U-Bar Ranch property along the Gila River from critical habitat for the narrow-headed gartersnake. NMDA stated that voluntary conservation planning and actions on the property are adequate for conserving the species. Freeport-McMoRan Tyrone Inc. and Pacific Western Land Company (collectively known as “FMC”) also commented that lands owned by FMC along the upper Gila River in the Gila/Cliff Valley, Grant County, New Mexico, should be excluded from critical habitat pursuant to section 4(b)(2) of the Act based on their habitat management plans for spikedace (
Meda fulgida
) and loach minnow (
Rhinichthys cobitis
) and for southwestern willow flycatcher (
Empidonax traillii extimus
). They stated that these management plans protect and support habitat for aquatic and riparian species, including native prey species for the narrow-headed gartersnake.

Our Response:
Consideration of possible exclusions from critical habitat are in our discretion and generally follow our Policy Regarding Implementation of Section 4(b)(2) of the Endangered Species Act (81 FR 7226; February 11, 2016). In response to FMC's request to exclude their lands along the upper Gila River based on FMC habitat management plans for spikedace and loach minnow and for grazing management actions benefiting southwestern willow flycatcher, we have determined that the exclusion would not be appropriate for several reasons. Although we commend FMC for investing time, effort, and funding for conservation on the Gila River, the habitat conservation efforts to date that have been implemented are focused on management actions for spikedace, loach minnow, and southwestern willow flycatcher along the Gila River. There are no conservation efforts specific to the narrow-headed gartersnake included in these plans. In identifying critical habitat for the narrow-headed gartersnake, we identified those areas that meet the definition of critical habitat under section 3(5)(A) of the Act. Although management actions for one listed species may overlap other species' habitat or be mutually beneficial to multiple listed species, the PBFs in occupied habitat for the narrow-headed gartersnake differ from the PBFs identified for spikedace, loach minnow, and southwestern willow flycatcher. As a result, excluding these areas based on management for listed fish and bird species does not meet our criteria for exclusion. With respect to the Upper Gila River Subbasin Unit for the narrow-headed gartersnake, we determined that the benefits of exclusion do not outweigh the benefits of inclusion. See Consideration of Impacts under Section 4(b)(2) of the Act,
Private or Other Non-Federal Conservation Plans or Agreements and Partnerships, in General,
below.

Comment 33:
NMDA commented that we should reconsider the value of critical habitat if we cannot identify a case in which consultation would require additional conservation measures.

Our Response:
We are required by section 4(a)(3) of the Act to designate critical habitat for listed species if we find that the designation is prudent and determinable, as we did for the narrow-headed gartersnake, regardless of whether we can foresee project modifications that may be required.

Comment 34:
NMDGF requested that we exclude developed, human-made fish migration barrier structures from critical habitat because including them will hinder conservation efforts for native fish and snakes by delaying construction and maintenance efforts of these structures.

Our Response:
When determining critical habitat boundaries, we made efforts to avoid including developed areas such as lands covered by buildings, pavement, and other structures because such lands lack the PBFs. The human-made fish barriers are in-water structures that fall within the boundaries of habitats used by narrow-headed gartersnakes. Because of this and the limitations of map scale, any developed lands, such as constructed fish barriers left inside critical habitat boundaries, are not considered critical habitat because they lack the necessary PBFs. However, a Federal action involving the fish barriers, such as maintenance, may trigger section 7 consultation with respect to critical habitat or the prohibition of adverse modification if the specific action would affect the PBFs in surrounding critical habitat.

Comment 35:
The New Mexico Interstate Stream Commission commented that the Service must complete an environmental impact statement (EIS) for designating critical habitat.

Our Response:
NEPA dictates that the Service determine the appropriate level of NEPA review (40 CFR 1501.3). The Service completed an environmental assessment (EA) to determine whether an EIS was necessary or if a finding of no significant impact (FONSI) could be determined. The Service released a draft EA that was available for public comment from December 18, 2020, to January 16, 2021, on the Arizona Ecological Services Field Office website; we received five comments on the draft EA. After addressing the public comments received, the Service finalized the EA and found that designating critical habitat for the narrow-headed gartersnake would not result in significant impacts to the environment. A copy of the final EA and FONSI is available at
http://www.regulations.gov
at Docket No. FWS-R2-ES-2020-0011. Therefore, the appropriate NEPA process was completed, and an EIS is not required.

Tribal Comments

In accordance with our requirements to coordinate with Tribes on a government-to-government basis, we solicited information from the following 17 Tribes regarding the designation of critical habitat for the narrow-headed gartersnake: Chemehuevi Indian Tribe, Cocopah Indian Tribe, Colorado River

Indian Tribes, Fort McDowell Yavapai Nation, Fort Mojave Indian Tribe, Gila River Indian Community (GRIC), Hopi Tribe, Hualapai Tribe, Mescalero Apache Tribe, Pascua Yaqui Tribe, Salt River Pima—Maricopa Indian Community, San Carlos Apache Tribe, Tohono O'odham Nation, Tonto Apache Tribe, White Mountain Apache Tribe, Yavapai-Apache Nation, and Yavapai-Prescott Indian Tribe. While all of these Tribes may have interest in lands included in proposed critical habitat for the narrow-headed gartersnake, the only Tribal land included in the revised proposed critical habitat designation (85 FR 23608; April 28, 2020) was land owned by the San Carlos Apache Tribe and the White Mountain Apache Tribe. We also met with representatives of the GRIC and White Mountain Apache Tribe to discuss this proposed designation. The GRIC expressed concern regarding potential effects that critical habitat may have on water allocation. In communications with the Service, the San Carlos Apache Tribe expressed interest in being excluded from the designation, and White Mountain Apache Tribe sent a letter requesting to be excluded from the designation.

Comment 36:
GRIC expressed concern about how designation of critical habitat for the narrow-headed gartersnake on the Gila and San Francisco Rivers might cause potential curtailment of water inflow to San Carlos Reservoir and subsequent downstream delivery to GRIC pursuant to their water rights settlement.

Our Response:
We do not anticipate water inflow to San Carlos Reservoir and subsequent downstream delivery of water to GRIC will be impacted by this critical habitat designation. The economic analysis outlines the substantial baseline protections currently afforded the narrow-headed gartersnake throughout the designation, and it includes a determination that the impacts of this critical habitat designation will be minimal (see Consideration of Impacts under Section 4(b)(2) of the Act,
Private or Other Non-Federal Conservation Plans Related to Permits Under Section 10 of the Act
).

Comment 37:
White Mountain Apache Tribe requested that the White Mountain Apache Homeland be excluded from the designation of critical habitat based on the White Mountain Apache Tribe's management and conservation of narrow-headed gartersnake habitat through several measures. These measures include formally approving the White Mountain Apache Native Fish Management Plan that includes prey species of the narrow-headed gartersnake; enacting Resolution 89-149 to designate streams and riparian zones as sensitive fish and wildlife areas; adopting a Water Quality Protection Ordinance to promote the health of Tribal waters and the people, plants, and wildlife that depend on them; and implementing overall holistic management of wildlife and natural resources within the Tribe's Homeland. White Mountain Apache Tribe also stated that the designation would infringe on Tribal sovereignty and directly interfere with Tribal self-government recognized as paramount in Joint Secretarial Order No. 3206.

Our Response:
We have reviewed the request for exclusion from the White Mountain Apache Tribe and excluded all Tribal lands from the final designation under section 4(b)(2) of the Act (see Consideration of Impacts under Section 4(b)(2) of the Act, below). Because all Tribal lands have been excluded from this final critical habitat designation, any required conservation activities on Tribal lands would be based solely on the presence of the narrow-headed gartersnake on Tribal lands due to the listing of the species as a threatened species under the Act (see 79 FR 38678; July 8, 2014).

Public Comments

Comment 38:
Several commenters stated that designating critical habitat for the narrow-headed gartersnake is not prudent because disclosing where individuals can be found would increase illegal taking of these species. Several commenters also stated that designating critical habitat is not prudent because most of the stream reaches included in the proposed designation have already been designated as critical habitat for other listed species.

Our Response:
As discussed in the final listing rule (79 FR 38678; July 8, 2014), there is no imminent threat of take attributed to illegal collection for this species, and identification and mapping of critical habitat is not expected to initiate any such threat.

Additionally, criteria used to determine if designation of critical habitat for the narrow-headed gartersnake is prudent pursuant to our regulations (50 CFR 424.12(a)(1)) may differ from criteria used to designate critical habitat for other listed species. Therefore, because none of the circumstances enumerated in our regulations at 50 CFR 424.12(a)(1) has been met and because there are no other circumstances we have identified for which this designation of critical habitat would not be prudent, we have determined that the designation of critical habitat is prudent for the species.

In development of the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we used the best scientific and commercial information available. In that revised proposed rule, we reassessed occupancy at the time of listing by reviewing all records for the narrow-headed gartersnake that we used in our original proposed critical habitat rule (78 FR 41550; July 10, 2013) in conjunction with expected survivorship of the species. We also used subsequent surveys in areas that had no detection of the species, and reviewed changes in threats that may have prevented occupancy at the time of listing. We determined that the best available information reflecting occupancy at the time of listing supports a more recent date of records since 1998, which includes areas within the United States (see Criteria Used To Identify Critical Habitat, below). This and other information represent the best scientific and commercial data available and led us to determine areas of occupancy at the time of listing. Our review of the best scientific and commercial data available supports the conclusion that the designation of critical habitat is prudent and determinable for the narrow-headed gartersnake.

Comment 39:
Multiple commenters stated that the available data are insufficient to identify the species' needs and impacts from wildfires in order to determine areas for critical habitat.

Our Response:
In development of the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we used the best scientific and commercial information available. We have sufficient information to determine the areas essential to the conservation of the species (
i.e.,
critical habitat) as documented in the 2020 revised proposed rule. In addition to reviewing narrow-headed gartersnake-specific survey reports, we also focused on survey reports and heritage data for fish and amphibians from State wildlife agencies, as they captured important data on the existing community ecology that affects the status of the narrow-headed gartersnake. In addition to species data sources, we used publicly available geospatial datasets depicting water bodies, stream flow, vegetation type, and elevation to identify critical habitat areas. We reviewed the available information pertaining to the biological needs of the species and habitat characteristics where the species is located. This and other information represent the best scientific and commercial data available and led us to

conclude that the designation of critical habitat is determinable for the narrow-headed gartersnake.

As discussed in the final listing rule (79 FR 38678; July 8, 2014), landscape-scale wildfires have impacted the species and its habitats. We understand that wildfires can cause sedimentation that can reduce water quality and prey availability for the narrow-headed gartersnake, and we included areas in critical habitat that had records of the species from 1998 to 2019, but that may need special management to maintain PBFs 1 and 3 as a result of recent or future wildfires.

Comment 40:
Two commenters stated that ephemeral reaches of streams, as well as intermittent streams, can provide habitat for narrow-headed gartersnakes. Gartersnakes use them on a seasonal basis, and they may have lower densities of nonnative aquatic species. Therefore, they should be included in the critical habitat designation.

Our Response:
In development of the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we clarified the spectrum of stream flow regimes that provide stream habitat for the narrow-headed gartersnake based on scientifically accepted stream flow definitions (Levick
et al.
2008, p. 6; Stromberg
et al.
2009, p. 330). We define a “spatially intermittent” stream as a stream that is interrupted, perennially interrupted, or spatially intermittent; has perennial flow occurring in areas with shallow bedrock or high hydraulic connectivity to regional aquifers; and has ephemeral to intermittent flow occurring in areas with deeper alluvial basins or greater distance from the headwaters (Stromberg
et al.
2009, p. 330). The spatial patterning of wet and dry reaches on spatially intermittent streams changes through time in response to climatic fluctuations and to human modifications of the landscape (Stromberg
et al.
2009, p. 331).

We explain that streams that have perennial or spatially intermittent flow can provide stream habitat for the species (Levick
et al.
2008, p. 6; Stromberg
et al.
2009, p. 330) (see “Stream Flow” in 85 FR 23608, April 28, 2020, p. 23613; and Physical or Biological Features Essential to the Conservation of the Species, below). While streams with intermittent flow reaches do serve as habitat for narrow-headed gartersnakes and are included in the designation, ephemeral streams do not. Within the range of the narrow-headed gartersnake, perennial streams become ephemeral as they approach their headwaters. Narrow-headed gartersnakes have not been found in these ephemeral reaches because fish communities become sparse to nonexistent in these areas so that the gartersnake prey base is likely absent. In addition, there is no upstream habitat above the headwaters of a stream, so these ephemeral reaches do not provide connectivity and are not included in critical habitat.

Comment 41:
One commenter stated that we should maintain a shoreline component as part of the PBFs that identify critical habitat. They stated their view that eliminating the shoreline component could result in improperly leaving out habitats that narrow-headed gartersnakes use because they span the transition between upland riparian and in-stream habitats.

Our Response:
We do not use the term “shoreline habitat” in the PBFs for the narrow-headed gartersnake because shorelines fluctuate. Instead, we are focusing on the substrate. The key to the original primary constituent element for “shoreline habitat” was the substrate itself, not the fluctuating shoreline. The revised PBF 1 focuses on the organic and natural inorganic structural features important to the narrow-headed gartersnake that fall within the stream channel and still encompass the transition between in-stream habitat and land habitat.

Comment 42:
One commenter stated that there are no currently available data on the effects of pollutants on the recruitment of narrow-headed gartersnakes; therefore, including PBF 1(C) for the narrow-headed gartersnake, which concerns water quality with low to zero levels of pollutants, is not using the best available science.

Our Response:
We do not have specific data related to the effects of water pollutants on the recruitment of the narrow-headed gartersnake. Therefore, in this rule, we have amended the relevant PBF to read as follows: “Water quality that meets or exceeds applicable State surface water quality standards.” (For more information, see Physical or Biological Features Essential to the Conservation of the Species, below). Although water quality is not identified as a direct threat to the narrow-headed gartersnake, it is a threat to its prey base. Water quality that is absent of pollutants or has low levels of pollutants is needed to support the fish prey base for the narrow-headed gartersnake. State water quality standards identify levels of pollutants required to maintain communities of organisms that have a taxa richness, species composition, and functional organization that includes the fish prey base of the narrow-headed gartersnake.

Comment 43:
Two commenters stated that 89 ft (27 m) from the water's edge does not capture the lateral distance from streams that individual narrow-headed gartersnakes moved for brumation in Oak Creek Canyon, Arizona, which is between 276 and 328 ft (84 and 100 m).

Our Response:
We agree that terrestrial habitat as defined in PBF 1(D) for the narrow-headed gartersnake does not include all known brumation sites for the species, including several sites located on steep slopes in Oak Creek Canyon that we discussed in the revised proposed rule (see “Terrestrial Space Along Streams,” 85 FR 23608, April 28, 2020, pp. 23614-23616). In the 2020 revised proposed rule, we modified that lateral extent boundary of critical habitat to 89 ft from the active channel of a stream based on the greatest average distance moved from water during the wet season on the Tularosa River in New Mexico from a 3-year study with a sample size of 69 individuals at two different sites. Because this study was conducted during the active season, it does not include brumation sites. We also did not include areas for brumation in PBF 1(D) for the narrow-headed gartersnake. This was an oversight, and we have added brumation to PBF 1(D) for narrow-headed gartersnake in this final rule. As a result, we have also increased the lateral extent of critical habitat for the narrow-headed gartersnake up to 328 ft (100 m) from the water's edge, so that critical habitat includes additional areas for brumation along streams within narrow-walled canyons such as Oak Creek Canyon in Arizona (see
Summary of Essential Physical or Biological Features,
below). All areas included in this final rule as a result of increasing the lateral extent of critical habitat units was proposed as critical habitat for the narrow-headed gartersnake in the 2013 original proposed critical habitat rule (78 FR 41550; July 10, 2013).

Comment 44:
One commenter stated that the proposed critical habitat for the narrow-headed gartersnake in Eagle Creek in Greenlee County, Arizona, lacks recent detections, is primarily on Tribal land, and lacks habitat for the species because it is dominated by nonnative aquatic predators.

Our Response:
In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we reviewed gartersnake occupancy to determine that a stream or stream reach was occupied at the time of listing for the narrow-headed gartersnake if it is within the historical range of the species, contains

PBFs for the species (although the PBFs concerning prey availability and presence of nonnative aquatic predators are often in degraded condition), and has a last known record of occupancy between 1998 and 2019 (see Occupancy Records, 85 FR 23608, p. 23617-23619) (see Criteria Used To Identify Critical Habitat). The segment of Eagle Creek included in critical habitat for the narrow-headed gartersnake meets this definition, but the areas of it owned by the San Carlos Apache Tribe were excluded from this final designation.

Comment 45:
One commenter stated that we should determine occupancy at the time of listing (2014) from 1980 to today, as was done in the original proposed critical habitat rule (78 FR 41550; July 10, 2013), rather than 1998 to today, which was done in the revised proposed critical habitat rule (85 FR 23608; April 28, 2020). Repeated discoveries of populations of narrow-headed gartersnakes that were thought to be lost or were unknown indicates using 1980 as the earliest year to determine occupancy at the time of listing is therefore more appropriate. A lack of documentation of occupancy reflects incomplete survey effort rather than true non-occupancy.

Our Response:
As explained extensively in the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), although it is possible that narrow-headed gartersnakes are still extant in areas where they were detected only during the 1980s or prior, we have determined that the best available information reflecting occupancy at the time of listing supports a more recent date of records since 1998.

Based on our analyses in the listing rule (79 FR 38678; July 8, 2014), we conclude that there has been a significant decline in the species over the past 50 years. This decline appeared to accelerate during the two decades immediately before listing occurred. From this observation, we conclude that many areas that were occupied by the species in surveys during the 1980s are likely no longer occupied because those populations have likely disappeared. To determine where loss of populations was most likely, we reviewed survey efforts after 1989 that did not detect narrow-headed gartersnakes in some of the areas included in the original proposed critical habitat rule (78 FR 41550; July 10, 2013). All surveys conducted since the 1980s that were considered included at least the same amount or more search effort than those surveys that detected the species in the 1980s. Since 1998, researchers have detected narrow-headed gartersnakes in many areas where they were found in the 1980s, and this includes some areas where they had not been found prior to the 2014 final listing rule (see Criteria Used To Identify Critical Habitat, below). An increase in a species' detection information often occurs as a result of a species being listed as an endangered or threatened species, due to increased survey effort spurred by consultation requirements under section 7, as well as recovery actions or State coordination efforts under section 6, of the Act. Additional occupancy information is also sometimes obtained as a result of academic research on a species. Because the best available information supports a conclusion that these areas were occupied at the time of listing, we have included these areas in critical habitat (see Criteria Used To Identify Critical Habitat, below).

Comment 46:
Multiple comments suggested we consider using longer stream lengths to determine gartersnake occupancy. A species might use a stream's entire wetted length, rather than just certain reaches, and the narrow-headed gartersnake had previously been connected in large stretches of river that are part of high-quality contiguous riparian habitat.

Our Response:
In the original proposed critical habitat rule (78 FR 41550; July 10, 2013), we included the entire stream length of a perennial or intermittent stream if it had at least one known record for the narrow-headed gartersnake and at least one record of a native prey species present. In doing so, we included many areas that were not within the known range of the species, did not have records of the species, or did not contain the PBFs. For the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we reevaluated all streams based on comments and reports on water availability, prey availability, and surveys to determine which reaches contain the PBFs.

In the revised proposed critical habitat rule (85 FR 23608; April 28, 2020) and this final rule, critical habitat includes occupied streams or stream reaches within the historical range with survey records of the narrow-headed gartersnake dated from 1998 to 2019 that have retained the necessary PBFs that will allow for the maintenance and expansion of existing populations. We placed outer boundaries on the portion of a stream that is considered occupied. We identified the most upstream and downstream records of the narrow-headed gartersnake along each continuous stream reach determined by presence of PBFs, and we extended the stream reach to include a dispersal distance of 2.2 mi (3.6 km). After identifying the stream reaches that meet the above parameters, we then connected those reaches with intervening areas that have the PBFs. We consider these intervening areas occupied because the species occurs upstream and downstream and multiple PBFs are present that allow the species to move through these stream reaches.

Comment 47:
One commenter stated that critical habitat should include areas where native prey is limited and/or where nonnative species are present, for both occupied and unoccupied critical habitat, because narrow-headed gartersnakes can survive with low natural prey populations and the presence of nonnatives. Another commenter stated that we should not exclude stream reaches where other Federal, State, Tribal, or private entities may stock predatory sportfish regularly or as needed, because recovery of listed species should be prioritized in those areas.

Our Response:
This critical habitat designation includes many areas that are occupied by the narrow-headed gartersnake, where native prey is limited, and where nonnative species that prey on gartersnakes are present. Please see Final Critical Habitat Designation, below, for unit descriptions, including why units meet the definition of critical habitat for the narrow-headed gartersnake.

Areas subject to stocking of predatory sportfish are not occupied by the narrow-headed gartersnake. We have not identified any unoccupied areas that meet the definition of critical habitat. Please see our response to
Comment 50,
below.

Comment 48:
One commenter stated that the gartersnake is currently distributed in stream reaches that are dominated by nonnative vertebrates and crayfish; therefore, the best available science does not support excluding areas as critical habitat based on an abundance of nonnative aquatic predators.

Our Response:
We acknowledge that the narrow-headed gartersnake is extant in some areas that have abundant nonnative aquatic predators, some of which also are prey for gartersnakes, so the presence of nonnative aquatic predators is not always indicative of absence of the gartersnake (Holycross
et al.
2006). Although we acknowledge that we do not have a thorough understanding of narrow-headed gartersnake population dynamics in the presence of nonnative aquatic predators as compared to other areas, areas with aquatic predators that are currently known to support gartersnake

populations are included in this critical habitat designation. That said, we think it is reasonable to conclude, based on the best scientific data currently available, that streams or stream reaches should not be included in the final designation if the last known occupancy is prior to 1998 and the stream reaches have experienced a rapid decline in native prey species coupled with an increase in nonnative aquatic predators since gartersnakes were detected in these areas prior to 1998 (85 FR 23608; April 28, 2020).

Comment 49:
Several commenters stated that designation of unoccupied critical habitat is needed for the narrow-headed gartersnake. Specifically, habitat fragmentation, small populations, and genetics threaten the species with extinction and thus make unoccupied critical habitat essential. Designating unoccupied habitat is also important to restore connectivity among populations, and the Service should also consider reintroduction of the gartersnake to unoccupied areas.

Our Response:
As discussed in the final listing rule (79 FR 38678; July 8, 2014), continued population decline and extirpations threaten the genetic representation of the narrow-headed gartersnake because some populations have become disconnected and isolated from neighboring populations. This can lead to a reduction in the species' redundancy and resiliency when isolated, small populations are at increased vulnerability to the effects of threats and stochastic events, without a means for natural recolonization.

As required by section 4(b) of the Act, we use the best scientific and commercial data available in determining areas within the geographical area occupied at the time of listing that contain the features essential to the conservation of the species and which may require special management considerations or protection, and areas outside of the geographical area occupied at the time of listing that are essential for the conservation of the species. However, based on the best scientific data available we have not identified any unoccupied areas that are essential for the conservation of the species. While we know the conservation of the species will depend on increasing the number and distribution of populations of the narrow-headed gartersnake, not all of its historical range will be essential to the conservation of the species, and we are unable to delineate any specific unoccupied areas that are essential at this time. A number of areas within these watersheds continue to contain some or could develop many of the PBFs upon which the species depends, although the best available scientific data indicate all these areas are currently unoccupied. Some areas in these watersheds with the potential to support the PBFs are likely important to the overall conservation strategy for the narrow-headed gartersnake. Any specific areas essential to the species' conservation within these watersheds are not currently identifiable due to our limited understanding regarding the ideal configuration for the development of future habitat to support the narrow-headed gartersnake's persistence, and the ideal size, number, and configuration of these habitats. Although there may be a future need to expand the area occupied by the species to reach recovery, these areas have not been identified in recovery planning for the narrow-headed gartersnake. Therefore, we cannot identify unoccupied areas that are currently essential to the conservation of the species that should be designated as critical habitat.

Comment 50:
One commenter stated that only including areas occupied by the species at the time of listing does not allow for naturally occurring range expansion into other areas with suitable habitat that already exist or are newly created from habitat restoration activities.

Our Response:
Limiting critical habitat to areas occupied by a species at the time of listing does not prevent a species from naturally expanding into other areas. As discussed in the final listing rule (79 FR 38678; July 8, 2014), continued population decline and extirpations threaten the genetic representation of the narrow-headed gartersnake because some populations have become disconnected and isolated from neighboring populations. This can lead to a reduction in the species' redundancy and resiliency when isolated, small populations are at increased vulnerability to the effects of threats and stochastic events, without a means for natural recolonization.

As required by section 4(b) of the Act, we use the best scientific and commercial data available in determining areas within the geographical area occupied at the time of listing that contain the features essential to the conservation of a species and which may require special management considerations or protection, and areas outside of the geographical area occupied at the time of listing that are essential for the conservation of the species. However, based on the best scientific data available we have not identified any unoccupied areas that that are essential for the conservation of the species. While we know the conservation of the species will depend on increasing the number and distribution of populations of the narrow-headed gartersnake, not all of the species' historical range will be essential to the conservation of the species, and we are unable to delineate any specific unoccupied areas that are essential at this time. A number of areas within these watersheds continue to contain some, or could develop many, of the PBFs upon which the species depends, although the best available scientific data indicate all these areas are currently unoccupied. Some areas in these watersheds with the potential to support the PBFs are likely important to the overall conservation strategy for the narrow-headed gartersnake. Any specific areas essential to the species' conservation within these watersheds are not currently identifiable due to our limited understanding regarding the ideal configuration for the development of future habitat to support the narrow-headed gartersnake's persistence, and the ideal size, number, and configuration of these habitats. Although there may be a future need to expand the area occupied by the species to reach recovery, these areas have not been identified in recovery planning for the narrow-headed gartersnake. Therefore, we cannot identify unoccupied areas that are currently essential to the conservation of the species that should be designated as critical habitat.

Comment 51:
One commenter stated that there are recent sightings of narrow-headed gartersnakes in Turkey Creek (which is part of the Upper Gila River Subbasin), so this area should not have been removed from the original proposed critical habitat designation.

Our Response:
This record was from 2020, and we are not aware of any confirmed records between 1998 and 2019, as delineated in our rule set (see Occupancy Records, 85 FR 23608, p. 23617-23619) (see Criteria Used To Identify Critical Habitat), that document the narrow-headed gartersnake in Turkey Creek, so this site is not included in our critical habitat designation because it does not meet the definition of an occupied reach for the species.

Comment 52:
One commenter requested confirmation that upper and lower Oak Creek have been removed from critical habitat, both of which have recent sightings of narrow-headed gartersnakes.

Our Response:
This area has not been removed from the critical habitat designation. In the revised proposed critical habitat rule (85 FR 23608; April

28, 2020), we reviewed gartersnake occupancy to determine that a stream or stream reach was occupied at the time of listing for narrow-headed gartersnake if it is within the historical range of the species, contains PBFs for the species (although the PBFs concerning prey availability and presence of nonnative aquatic predators are often in degraded condition), and has a last known record of occupancy between 1998 and 2019. The segment of Oak Creek from its confluence with Sterling Canyon downstream to 800 ft before its confluence with Turkey Creek meets this definition and is included in this critical habitat designation for the narrow-headed gartersnake.

Comment 53:
Several commenters stated that our use of historical data spanning two decades to characterize areas of critical habitat that are “occupied at the time of listing” for purposes of a designation under section 3(5)(A)(i) of the Act is not synonymous with a determination that habitat is currently occupied for purposes of a “take” analysis under sections 7 and 10 of the Act, and that the distinction between these two concepts needs to be fully acknowledged and its implications explained in the final rule.

Our Response:
We designate areas as critical habitat that are occupied at the time of listing if those areas have one or more of the PBFs present that are essential to the conservation of the species and may require special management considerations or protection (see 81 FR 7414; February 11, 2016). In the 2020 revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we estimated that maximum longevity for the narrow-headed gartersnake is 15 years, so it is reasonable to conclude that a gartersnake detected between 1998 and 2019 represents a population that could still be present at the time of listing in 2014, depending on the extent of threats in the area. We also included narrow-headed gartersnake detections after the species was listed because these areas were likely occupied at the time of listing in 2014. As a result, there are areas in this final designation of critical habitat with records of gartersnakes from 1998 through 2019.

Under section 7 of the Act, Federal agencies are required to consult with the Service to ensure that the actions they carry out, fund, or authorize are not likely to jeopardize the continued existence of the species, or destroy or adversely modify critical habitat. For a jeopardy or “take” analysis, we analyze effects to a species if the species is present in the action area during the time of the action. For an adverse modification analysis, we analyze effects to critical habitat if critical habitat for a species is present in the action area. Therefore, defining where a species is occupied at the time of listing for critical habitat designation is not synonymous with a determination that an area is currently occupied for purposes of a jeopardy analysis under section 7 of the Act or a “take” analysis under section 10 of the Act. Those determinations depend on the best available information at the time of the analysis, and the likely effects and likelihood of take depend on the action under consideration.

Comment 54:
One commenter stated that livestock grazing would have a significant impact on habitat for the narrow-headed gartersnake and that special management considerations and protection would benefit the species.

Our Response:
As discussed in the final listing rule (79 FR 38678; July 8, 2014), livestock grazing is a largely managed land use, and, where closely managed, it is not likely to pose significant threats to the narrow-headed gartersnake. In cases where poor livestock management results in fence lines in persistent disrepair, allowing unmanaged livestock access to occupied habitat, adverse effects from loss of vegetative cover, sedimentation, or alteration of prey base may result. Activities that significantly reduce cover or increase sedimentation are addressed below under
Application of the “Adverse Modification” Standard
and Special Management Considerations or Protection.

Comment 55:
One commenter stated that while we note that critical habitat units that have nonnative fish require special management, we do not explain how this management will be accomplished or whether it is even possible to reduce nonnatives to a level that will support narrow-headed gartersnakes.

Our Response:
We expect the science of removing nonnative fish will continue to evolve over time; for that reason, we did not prescribe specific methods of special management as part of this final designation. At this time, in the areas that require management of nonnative fish, special management may involve using mechanical or chemical methods to remove nonnative, invasive fish species.

Comment 56:
One commenter requested that we include a statement regarding the application of the “adverse modification” standard that existing activities are part of the baseline and, therefore, are presumed not to adversely modify critical habitat. The commenter further stated that we should affirmatively state that “adverse modification” will not be found where the agency, working with the project proponent, demonstrates that it will offset impacts to critical habitat through the protection and maintenance of alternative habitat within the designation, which is of comparable quality to the habitat that would be lost.

Our Response:
Section 7 of the Act requires us to ensure that any action authorized, funded, or carried out by the agency is not likely to destroy or adversely modify critical habitat. Therefore, only Federal action agencies are directly subject to the specific regulatory requirement (avoiding destruction and adverse modification) imposed by critical habitat designation. This adverse modification standard does not change whether the activities are ongoing or new, and we do not have a mechanism to determine that existing activities are presumed to not destroy or adversely modify critical habitat. Any new activity under section 7 will require evaluation of the effects of the action based on the specifics of the location of the project and its effects.

Comment 57:
Several commenters stated that we should consider an increased scope of economic impacts to small entities for the critical habitat rule. They also stated that the economic impact of the proposed designation would be significant on agricultural and ranching operations.

Our Response:
For the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we made available, and requested public comments on, a draft economic analysis (DEA) to examine the incremental costs associated with the designation of critical habitat. Our DEA did not find that there would be significant economic impacts to agriculture from this designation of critical habitat. This analysis includes impacts to third-party entities, such as local governments and private landowners. Critical habitat does not restrict private landowner access to their property, and private landowners would only need to consult with the Service under section 7 of the Act if Federal agency funding or permitting for an activity is needed. Because the areas are considered occupied, most costs are not associated with the critical habitat designation, but rather with listing of the species as threatened. In our mapping of critical habitat, we focused on areas that contain the PBFs for the species. We do not anticipate requesting additional modifications for livestock grazing or agricultural operations, or cost-share projects undertaken with agencies such as the U.S. Department of Agriculture's Natural Resources

Conservation Service (NRCS), as a result of the critical habitat designation beyond those required for the species itself. The economic analysis outlines the substantial baseline protections currently afforded the narrow-headed gartersnake through its listed status under the Act and the presence of the species in all designated critical habitat units, as well as overlap with the designated critical habitat of other, similar listed species. As a result of these protections, the economic analysis concludes that incremental impacts associated with section 7 consultations for the narrow-headed gartersnake are likely limited to additional administrative effort. Many of the areas designated as critical habitat for the narrow-headed gartersnake are already designated critical habitat for other listed species, and thus the designation of critical habitat for the narrow-headed gartersnake is not anticipated to cause an incremental increase in economic effects.

However, we recognize the potential for landowners' perceptions of the Act to influence land use decisions, including decisions to participate in Federal programs such as those managed by NRCS. Several factors can influence the magnitude of perception-related effects, including the community's experience with the Act and understanding of the degree to which future section 7 consultations could delay or affect land use activities. Information is not available to predict the impact of the designation of critical habitat on landowners' decisions to pursue cost-share projects with NRCS in the future. However, incremental effects due to the designation of critical habitat for the narrow-headed gartersnake are likely to be minimized because the species is already listed.

Comment 58:
One commenter requested we update the economic analysis to account for the impact of COVID-19 on economic conditions.

Our Response:
We do not anticipate any additional effects on economic conditions as a result of the impact of the COVID-19 pandemic. For the revised proposed critical habitat rule (85 FR 23608; April 28, 2020), we made available, and requested public comments on, our DEA to examine the incremental costs associated with the designation of critical habitat. The DEA did not identify significant impacts. Because the critical habitat areas are considered occupied, the majority of costs are not associated with the critical habitat designation, but rather with listing of the species as threatened. If Federal funding is involved, the Federal agency providing the funding is the party responsible for meeting the Act's obligations to consult on projects on private lands. We have considered and applied the best available scientific and commercial information in determining the economic impacts associated with designating critical habitat. Critical habitat designation may also generate ancillary benefits by protecting the PBFs on which the species depends. As a result, management actions undertaken to conserve the species or its habitat may have coincident, positive social welfare implications, such as increased recreational opportunities in a region or improved property values on nearby parcels.

Background

Critical habitat is defined in section 3 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' life cycle, 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 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 Federal agencies 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. Where a landowner requests Federal agency funding or authorization for an action that may affect a listed species or critical habitat, the Federal agency would be required to consult with the Service under section 7(a)(2) of the Act. However, even if the Service were to conclude that the proposed activity would 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.

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 and commercial data available, those physical or biological features that are essential to the conservation of the species (such as space, food, cover, and protected habitat). In identifying those physical or biological features that occur in specific occupied areas, we focus on the specific features that are essential to support the life-history needs of the species, including, but not limited to, water characteristics, soil type, geological features, 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.

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. The implementing regulations at 50 CFR 424.12(b)(2) further delineate unoccupied critical habitat by setting out three specific parameters: (1) When designating critical habitat, the Secretary will first evaluate areas occupied by the species; (2) the Secretary will only consider unoccupied areas to be essential where a critical habitat designation limited to geographical areas occupied by the species would be inadequate to ensure the conservation of the species; and (3) for an unoccupied area to be considered essential, the Secretary must determine that there is a reasonable certainty both that the area will contribute to the conservation of the species and that the area contains one or more of those physical or biological features essential to the conservation of the species.

Section 4 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 from the 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.

Habitat is dynamic, and species may move from one area to another over time. We recognize that critical habitat designated at a particular point in time may not include all of the habitat areas that we may later determine are necessary for the recovery of the species. For these reasons, 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. Federally funded or permitted projects affecting listed species outside their designated critical habitat areas may still result in jeopardy findings in some cases. 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 available information 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, 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 that 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 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.

Summary of Essential Physical or Biological Features

We derive the specific physical or biological features essential to the conservation of the narrow-headed gartersnake from studies of the species' habitat, ecology, and life history as described below. Additional information can be found in the proposed and final listing rules published in the
Federal Register
on July 10, 2013 (78 FR 41500), and July 8, 2014 (79 FR 38678), respectively. The physical or biological features identified here focus primarily on foraging and dispersal habitat and secondarily on thermoregulation, shelter, and brumation habitat because most of the habitat relationship research data derived from studies of these activities for the narrow-headed gartersnake.

We define the stream flow regimes that provide stream habitat for the narrow-headed gartersnake based on stream flow definitions in Levick
et al.
(2008, p. 6) and Stromberg
et al.
(2009, p. 330). A perennial stream or portion of a stream is defined as having surface flow continuously year-round, except for infrequent periods of severe drought (Levick
et al.
2008, p. 6). An intermittent stream is a stream where portions flow continuously only at certain times of the year (Levick
et al.
2008, p. 6). An intermittent strea

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2021-20962. Public record. Not legal advice.