The Sikes Act: An Overview of Conservation on Military Lands

The Sikes Act: An Overview of Conservation

on Military Lands

June 6, 2025

Congressional Research Service

https://crsreports.congress.gov

R48561

SUMMARY

The Sikes Act: An Overview of Conservation on

Military Lands

R48561

June 6, 2025

Eric P. Nardi

Analyst in Natural

The Department of Defense (DOD) manages hundreds of military installations across

Resources Policy

approximately 26 million acres of land in the United States. Lands under the jurisdiction of DOD

are managed to support military readiness and national defense priorities above other purposes.

At times, this focus has conflicted with DOD’s obligations to conserve natural resources under

environmental laws. In response, Congress has provided DOD with authorities to help frame

environmental considerations within the context of military missions. One example is Title I of

the Sikes Act (16 U.S.C. §§670-670f), which Congress has structured to provide DOD with flexibility to conserve natural

resources on military installations to the extent possible without negatively impacting readiness.

The Sikes Act directs the Secretary of Defense, in cooperation with the Secretary of the Interior and state fish and wildlife

agencies, to carry out a program for the conservation and rehabilitation of natural resources on military installations. The act

provides for the sustainable, multipurpose use of natural resources (subject to military security and safety requirements) and

the use of nature-based actions to improve resilience at military installations. The Secretary of the Interior acts through the

U.S. Fish and Wildlife Service (FWS) to implement the Department of the Interior’s Sikes Act responsibilities.

The Sikes Act defines military installations to mean any land or interests in land owned by the United States and

administered by the DOD, except land under the jurisdiction of the Assistant Secretary of the Army for Civil Works. Military

installations include all public lands withdrawn from the public domain for military uses. In addition, the Sikes Act may

cover state-owned National Guard installations. The Sikes Act applies to U.S. military installations located in the states, the

District of Columbia, and U.S. territories; it does not provide for U.S. bases abroad.

The Sikes Act directs the Secretary of Defense to ensure U.S. military installations develop and implement a comprehensive

plan for conservation and management of significant natural resources, known as an Integrated Natural Resources

Management Plan (INRMP). INRMPs are long-term planning documents that outline how each military installation with

significant natural resources will manage and integrate those resources with military mission requirements. As mandated

under the Sikes Act, INRMPs are to address the management of natural resources (e.g., fish and wildlife and related habitat,

land management, outdoor recreation, public access); the establishment of specific natural resource management objectives;

the integration of the various activities conducted under the plan; the enforcement of applicable natural resource laws and

regulations while ensuring no net loss in the capability of installation lands to support the military mission; and other

activities that DOD determines appropriate.

INRMPs are developed in cooperation with FWS and the appropriate state fish and wildlife agencies. Additionally, the Sikes

Act authorizes the Secretaries of military departments to enter into interagency agreements with other federal agencies and

cooperative agreements with states, local governments, tribes, nongovernmental organizations, and individuals to maintain

and improve natural resources on and around military installations in furtherance of INRMPs.

Revenue to support conservation activities under the Sikes Act comes from several sources. DOD installations may collect

hunting and fishing permit fees and use these funds for conservation activities at the installation where they were collected.

DOD also has authority to use some receipts collected from timber harvesting and grazing activities on military lands for

conservation purposes. Congress included authorizations of appropriations provisions for DOD and the Department of the

Interior (DOI) in the Sikes Act for many years, most recently through FY2019. DOD and DOI have seldom requested

funding under the distinct budget authority of the Sikes Act; instead, the agencies typically use funding from broader

appropriations authorities to implement Sikes Act responsibilities. Consequently, it can be difficult to track appropriations

specific to the Sikes Act.

Congress has used INRMPs as a means to address complex conservation issues on military lands. For example, in 2003,

Congress exempted military installations with finalized INRMPs from critical habitat designations under the Endangered

Species Act (16 U.S.C. §§1531-1544), provided the Secretary of the Interior determines the INRMP provides benefits to

listed species. In 2022, Congress mandated that INRMPs incorporate management, control, and eradication of invasive

species at military installations. Moving forward, Congress may further consider using INRMPs as a mechanism to address

environmental issues on military lands.

Congressional Research Service

The Sikes Act: An Overview of Conservation on Military Lands

Contents

Introduction ..................................................................................................................................... 1

Conservation Issues on Military Lands ........................................................................................... 2

Sikes Act Overview ......................................................................................................................... 3

Integrated Natural Resources Management Plans ........................................................................... 5

Required Content for Integrated Natural Resources Management Plans .................................. 6

Integrated Natural Resources Management Plan Approval Process and Reporting

Requirements ......................................................................................................................... 8

Interaction of the Sikes Act with the Endangered Species Act ................................................. 8

Cooperative Agreements and Partnerships ...................................................................................... 9

Funding for Sikes Act Implementation........................................................................................... 11

Considerations for Congress.......................................................................................................... 12

Contacts

Author Information........................................................................................................................ 13

Congressional Research Service

The Sikes Act: An Overview of Conservation on Military Lands

Introduction

The Department of Defense (DOD) manages approximately 26 million acres of land in the United

States across hundreds of military installations.1 Lands under DOD jurisdiction support activities

to ensure military readiness, among other purposes. This emphasis on military readiness

sometimes creates tension with DOD’s responsibilities to manage natural resources on its lands.

In response, Congress has authorized unique management arrangements to help DOD meet

environmental obligations and conserve natural resources. One of these authorities is Title I of the

Sikes Act (16 U.S.C. §§670-670f), which Congress has amended numerous times to address

complex conservation issues on military lands without curtailing installations’ military functions.

DOD lands contain a diverse range of species and ecosystems.2 They also generally are free of

urban and agricultural development and maintain ecological health. In 1960, Congress passed the

Sikes Act to authorize the conservation and protection of natural resources on DOD lands. Title I

of the Sikes Act directs DOD to carry out a program to provide for the conservation and

restoration of natural resources on military installations, including the use of nature-based

features to improve military resilience, and to provide access to sustainable multipurpose use of

natural resources on military installations (including hunting, fishing, and nonconsumptive uses),

subject to safety and military security restrictions.3

To support this program, the Sikes Act authorizes cooperation between DOD and the Department

of the Interior (DOI) and state fish and wildlife agencies to plan, develop, and maintain fish,

wildlife, and plant resources on military installations throughout the United States. The Secretary

of the Interior acts through the U.S. Fish and Wildlife Service (FWS) to implement DOI’s

responsibilities under the Sikes Act.4

Congress periodically addresses the Sikes Act in oversight hearings and actions that broadly

address the act’s effectiveness, areas for improving the act, and the act’s funding to implement

conservation activities. For example, Congress often considers amendments to the Sikes Act

during consideration of annual National Defense Authorization Acts (NDAAs); these bills serve

as a recurring opportunity for Congress to attend to the management of DOD lands, among other

defense-related matters.5

This report provides an overview of conservation on military installations under Title I of the

Sikes Act.6 The report also describes conservation issues on military lands and planning and

implementation requirements pursuant to the Sikes Act. Further, the report discusses sources of

funding for implementation of the Sikes Act. Finally, the report presents selected issues for

Congress.

1 Department of Defense (DOD), Base Structure Report FY2024, https://www.acq.osd.mil/eie/imr/rpid/library.html.

For information on the different kinds of military installations, see CRS In Focus IF11263, Defense Primer: Military

Installations Management, by Andrew Tilghman.

2 U.S. Fish and Wildlife Service (FWS), “Military Lands Conservation,” https://www.fws.gov/program/military-landsconservation.

3 16 U.S.C. §670a(a)(3).

4 FWS, “Sikes Act,” https://www.fws.gov/law/sikes-act.

5 For more information on National Defense Authorization Acts (NDAAs) generally, see CRS In Focus IF10515,

Defense Primer: The NDAA Process, by Valerie Heitshusen and Brendan W. McGarry.

6 Title II of the Sikes Act (16 U.S.C. §§670g- 670o) pertains to conservation on public lands outside of those managed

by DOD and is beyond the scope of this report.

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The Sikes Act: An Overview of Conservation on Military Lands

Conservation Issues on Military Lands

DOD is the third-largest federal land manager, behind DOI and the U.S. Department of

Agriculture.7 DOD lands contain ecologically significant ecosystems that support a wide variety

of fish and wildlife species, including more than 550 species that are federally listed as threatened

or endangered under the Endangered Species Act (ESA; 16 U.S.C. §§1531-1544).8 Of these, 54

listed species are found only on DOD lands.9

DOD lands are considered by some to be unique ecological preserves because they often

encompass publicly inaccessible areas that are devoid of agricultural uses and urban

development.10 Military installations are located in every state and U.S. territory and vary

considerably in size and function. DOD lands are used for many kinds of mission-related

purposes, including training exercises and research and development activities.

Routine military activities on DOD installations can impact natural resources. For instance, largescale exercises with surface vehicles (tracked and wheeled) and aircraft have been shown to

negatively impact ecosystems;11 studies have shown that repeated use of off-road vehicles can

destroy grasslands, reduce plant cover, and expose and compact soil.12 Military aircraft

sometimes collide with birds, and noise from overflights may interfere with acoustic

environments and may force wildlife to adapt to elevated noise levels or relocate.13 Aerial

bombing and surface gunnery ranges also modify landscapes and impact natural resources. In

addition, the military has a long history of using hazardous substances and testing munitions, and

7 DOD, Conserving Biodiversity on Military Lands: A Guide for Natural Resources Managers, 3rd ed., 2021, p. 207,

https://www.researchgate.net/publication/

357913404_Meeting_the_Military_Mission_Through_Conserving_Biodiversity_Chapter_1 (hereinafter DOD,

Conserving Biodiversity on Military Lands). For information on federal land ownership generally, see CRS Report

R42346, Federal Land Ownership: Overview and Data, by Carol Hardy Vincent and Laura A. Hanson.

8 DOD, Defense Environmental Programs Annual Report to Congress for Fiscal Year 2023, July 2024, p. 6,

https://www.denix.osd.mil/arc/denix-files/sites/6/2024/09/FY23-Defense-Environmental-Programs-Annual-Report-toCongress-508.pdf (hereinafter, DOD, Defense Environmental Program Annual Report FY2023).

9 DOD, Defense Environmental Programs Annual Report FY2023, p. 6. For additional context on endangered and

threatened species on military and other federal lands, see Bruce A. Stein et al., “Federal Lands and Endangered

Species: The Role of Military and Other Federal Lands in Sustaining Biodiversity,” BioScience vol. 58, no. 4 (April

2008), pp. 339-347.

10 DOD, Conserving Biodiversity on Military Lands, p. 207.

11 DOD, Conserving Biodiversity on Military Lands, p. 207; Michael J. Lawrence et al., “The Effects of Modern War

and Military Activities on Biodiversity and the Environment,” Environmental Reviews vol. 23, no. 4 (December 2015),

p. 444, https://doi.org/10.1139/er-2015-0039; Nathalie M. Armas, “Military Aviation Noise and Its Effects on

Domesticated and Wild Animals,” Penn State Environmental Law Review vol. 12, no. 2 (2004), pp. 381-384,

https://elibrary.law.psu.edu/pselr/vol12/iss2/4/.

12 DOD, Conserving Biodiversity on Military Lands, p. 207; John A. Guretzky and Alan B. Anderson, “Grazing and

Military Vehicle Effects on Grassland Soils and Vegetation,” Great Plains Research vol. 16, no. 1 (spring 2006), pp.

51-61, https://digitalcommons.unl.edu/greatplainsresearch/803/; Jeffrey S. Fehmi et al., Impacts of Military Vehicle

Training Activities on Vegetation: Bibliography with Abstracts, U.S. Army Corps of Engineers, Engineer Research and

Development Center, ERDC/CERL-SR-01-17, August 2001.

13 From 2007 to 2016, the U.S. Air Force and the U.S. Navy reported 45,440 and 11,112 wildlife strikes, respectively.

DOD estimated the cost of the damage from strikes to be more than $370 million. See DOD, “Bird/Wildlife Aircraft

Strike Hazard (BASH) Factsheet,” December 2018, https://www.denix.osd.mil/dodpif/denix-files/sites/37/2023/12/

DoD-PIF-BASH-Factsheet_508.pdf; For information on the effects of noise on wildlife, see National Park Service,

“Effects of Noise on Wildlife,” https://www.nps.gov/subjects/sound/effects_wildlife.htm.

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The Sikes Act: An Overview of Conservation on Military Lands

many military sites have documented environmental contamination from the use and improper

disposal of hazardous materials.14

Given the environmental impacts that military activities may cause, DOD is faced with the

challenge of considering the conservation of natural resources while ensuring installations are

managed to support military missions.15 The obligation to conserve natural resources on military

lands derives from several environmental statutes, including the ESA. However, given national

security considerations, Congress traditionally has provided the military with greater discretion in

managing its natural resources than that afforded to other federal land management agencies.16

For example, the conference report that accompanied the Bob Stump National Defense

Authorization Act for Fiscal Year 2003 (P.L. 107-314) noted,

The conferees believe that all federal agencies, including the Armed Forces, should be

required to comply with all federal environmental laws. However, due to their unique

military training and operational responsibilities, the Armed Forces often face unique

challenges in balancing the obligations to comply with environmental laws and sustain

military readiness. Examples of these challenges include increasing limitations and

restrictions on lands and waters which are currently set aside for military training exercises

as well as significant restrictions on the times and conditions under which training exercises

can be conducted.17

Sikes Act Overview

The Sikes Act, named for former Representative Robert L. F. Sikes, the sponsor of the legislation,

provides a framework for DOD to conserve and use natural resources on military installations

without compromising mission capabilities.18

The Sikes Act’s origins may be traced to P.L. 81-345, which directed the Secretary of the Air

Force “to carry out a program of planning, development, maintenance, and coordination of

wildlife, fish, and game conservation and rehabilitation” at Eglin Air Force Base (then known as

Eglin Field Reservation) in cooperation with the Secretary of the Interior, acting through FWS.

P.L. 81-345 directed the Secretary of the Air Force to promulgate regulations for conservation and

rehabilitation efforts in accordance with a plan to be mutually agreed upon with the Secretary of

the Interior. Further, the law granted the Secretary of the Air Force authority to issue hunting and

fishing permits for a nominal fee. These fees, in turn, were to be “utilized for restocking,

propagation, and other related wildlife activities” at Eglin.19

14 U.S. Environmental Protection Agency (EPA), “The Environmental Challenge of Military Munitions and Federal

Facilities,” https://www.epa.gov/enforcement/environmental-challenge-military-munitions-and-federal-facilities.

15 David Rubenson et al., More Than 25 Million Acres? DoD As a Federal, Natural, and Cultural Resource Manager,

prepared for the Office of the Secretary of Defense by RAND, National Defense Research Institute, 1996, p. x,

https://www.rand.org/content/dam/rand/pubs/monograph_reports/2007/MR715.pdf.

16 For examples of exemptions to natural resources laws for national defense purposes, see Curtis Cranston, “The U.S.

Military’s Environmental Protection Efforts: Unexpected Eco-Friendly Solutions to Land Management Problems,”

Boston College Law Review vol. 60 (2019), pp. 1036-1041, https://bclawreview.bc.edu/articles/293/files/

63a5436f3fc0c.pdf (hereinafter Cranston, “U.S. Military’s Environmental Protection Efforts”).

17 U.S. Congress, House of Representatives, National Defense Authorization Act for Fiscal Year 2003, conference

report to accompany H.R. 4546, 107th Cong., 2nd sess., H.Rept. 107-772, November 12, 2002, pp. 632-633.

18 For biographical information on Rep. Robert L. F. Sikes, see his entry in the Biographical Directory of the United

States Congress, https://bioguide.congress.gov/search/bio/S000406.

19 U.S. Congress, House Armed Services Committee, Authorizing Restocking, Propagation, and Conservation of Game

(continued...)

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The Sikes Act expanded the Eglin conservation program to all military installations in the United

States and authorized installations to enter into cooperative agreements with FWS and state

natural resources agencies to conserve natural resources on their lands. As originally enacted, the

law authorized, but did not require, DOD to develop conservation plans to conserve fish and

wildlife and permit public outdoor recreation access, where compatible with the military

mission.20

Congress has amended the Sikes Act on numerous occasions. As a result of these amendments,

the Sikes Act directs DOD to carry out a program to provide for (1) the conservation and

rehabilitation of natural resources on military installations; (2) the use of nature-based solutions

to maintain or improve military resilience; (3) the sustainable multipurpose use of natural

resources on military installations; and (4) public access to military installations for outdoor

recreation and other natural resources uses (subject to safety and military security

requirements).21

To facilitate this program, in 1997 Congress passed the Sikes Act Improvement Act (Title XXIX

of the National Defense Authorization Act for Fiscal Year 1998; P.L. 105-85), which made

cooperative conservation planning a requirement, through the development and implementation

of an Integrated Natural Resources Management Plan (INRMP), on each installation with

“significant natural resources.”22 INRMPs are to be developed and mutually agreed upon by

DOD, FWS, and the head of the appropriate state fish and wildlife agency.23 INRMPs are

planning documents that outline how each military installation with significant natural resources

will manage and integrate those resources with military mission requirements. The Sikes Act did

not define significant natural resources. DOD policy guidance has indicated that natural

resources may be significant at national, regional, or local scales and may include all species

listed, or at risk of being listed, as threatened and endangered species under the ESA.24

With certain exceptions, the Sikes Act applies to U.S. military installations located in the states,

the District of Columbia, and U.S. territories that possess significant natural resources.25 Military

installations include all public lands withdrawn from the public domain for military purposes.26 In

addition, the Sikes Act provides DOD with authority to develop and implement INRMPs for

state-owned National Guard installations used for training the National Guard under 32 U.S.C.

in the Eglin Field Reservation, report to accompany H.R.2418, 81st Cong., 1st sess., H.Rept. 81-622, May 11, 1949, pp.

1-2; Major Teresa K. Hollingsworth, “The Sikes Improvement Act of 1997: Examining the Changes for the Department

of Defense,” Air Force Law Review vol. 46 (1999), p. 112.

20 John Fittipaldi et al., Army Ecosystem Management Policy Study, Army Environmental Policy Institute, March 1997,

p. 4-1, https://apps.dtic.mil/sti/tr/pdf/ADA596817.pdf.

21 16 U.S.C. §670a(a)(3).

22 16 U.S.C. §670a(1)(B). Prior to the enactment of P.L. 105-85, conservation planning under the Sikes Act was

voluntary, and, according to some stakeholders, when plans were developed, they were inconsistent and incomplete.

See U.S. Congress, House Natural Resources Committee, Sikes Act Amendments Act of 2011, report to accompany

H.R. 1670, 112th Cong., 1st sess., H.Rept. 112-175, Pt. 1, July 21, 2011, p. 4 (hereinafter House Natural Resources

Committee, Sikes Act Amendments Act of 2011, H.Rept. 112-175 , Pt. 1).

23 16 U.S.C. §670a.

24 DOD Instruction 4715.03, Natural Resources Management, July 22, 2024, p. 33, https://www.esd.whs.mil/Portals/

54/Documents/DD/issuances/dodi/471503p.pdf (hereinafter DOD Instruction 4715.03).

25 16 U.S.C. §670. In 2011, under P.L. 112-81, Congress defined states to include “any of the several States, the

District of Columbia, the Commonwealth of Puerto Rico, Guam, the Commonwealth of the Northern Mariana Islands,

American Samoa, and the Virgin Islands.”

26 For background information on withdrawals, including military withdrawals, see Bureau of Land Management,

“Withdrawals,” https://www.blm.gov/programs/lands-and-realty/withdrawals.

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§§501-510, subject to the availability of appropriations.27 For the purposes of the Sikes Act,

military installations do not include land under the jurisdiction of the Assistant Secretary of the

Army for Civil Works or land that is subject to an approved recommendation for closure under

the Defense Base Closure and Realignment Act of 1990 (10 U.S.C. §2687).28

The Sikes Act does not address U.S. military installations abroad. Natural resources at

installations abroad generally are managed according to DOD policy directives, as most U.S.

environmental laws do not provide for international application. Additionally, foreign nations

may have environmental laws that impact the management of U.S. military assets and

installations. DOD may choose to use management frameworks from the Sikes Act for

installations abroad, but it is not required to do so.29

Integrated Natural Resources Management Plans

The Sikes Act directs DOD to develop an INRMP for each military installation in the United

States on which “significant natural resources” are present.30 The term significant natural

resources is not defined in the Sikes Act. DOD Instruction 4715.03 (which provides guidance for

natural resources management) states that “natural resources may be significant on a local,

regional, national, or international scale. All threatened or endangered species, and species at risk

occurring on installations, are significant natural resources that will normally require an

INRMP.”31

According to the DOD Environment, Safety, and Occupational Health Network and Information

Exchange, 364 of 550 DOD installations have INRMPs (164 Army, 78 Navy, 102 Air Force, 18

Marine Corps, and 2 Defense Logistics Agency).32 INRMPs are intended to guide a program to

provide for

•

•

•

the conservation and rehabilitation of natural resources on military installations;

the use of natural and nature-based features to maintain or improve military

installation resilience;

the sustainable multipurpose use of the resources on military installations,

including hunting, fishing, trapping, and nonconsumptive uses; and

27 16 U.S.C. §670a(a).

28 16 U.S.C. §670.

29 DOD Instruction 4715.03, p. 4, notes that “operations and activities outside the United States ... will follow the

policy guidance in [Executive Orders] 12114 and 12915, DOD [Instructions] 4715.05 and 4715.22, DOD [Manual]

4715.05, and Service-specific regulations.” Further, “outside the United States, DOD [Instruction] 4715.05 will apply,

in accordance with international agreements, status of forces agreements, final governing standards issued for host

nations, or, where no final governing standards have been issued, the criteria in DOD Manual 4715.05.” Final

governing standards are a comprehensive set of country-specific environmental authorities, including applicable

foreign environmental laws and regulations. For further discussion of these issues, see Mark P. Nevitt, “Environmental

Law in Military Operations,” in U.S. Military Operations: Law, Policy, and Practice, ed. Geoffrey S. Corn et al., (New

York: Oxford University Press, 2015), pp. 401-436, https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2665391. For

more information on DOD’s international environmental authorities, see DOD, “DoD International Environmental

Program,” https://www.denix.osd.mil/international/.

30 16 U.S.C. §670a; DOD Instruction 4715.03, p. 33.

31 DOD Instruction 4715.03, p. 33.

32 DOD, “The Department of Defense Natural Resources Program,” April 10, 2025, https://www.denix.osd.mil/nr/.

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The Sikes Act: An Overview of Conservation on Military Lands

•

public access to military installations to facilitate use of natural resources

(subject to safety requirements and military security).33

DOD is to prepare INRMPs in cooperation with FWS and state fish and wildlife agencies and is

to reach mutual agreement on the conservation, protection, and management of fish and wildlife

resources with these entities.34 DOD also may consult with other pertinent regulatory agencies

(e.g., the National Marine Fisheries Service [NMFS]) and stakeholders (e.g., tribes), as

applicable.35 According to DOD guidance, installations containing land withdrawn from the

public domain are to consult with the Bureau of Land Management in the development and

implementation of INRMPs.36 Withdrawn land represents a significant portion of real property

managed by DOD; as of 2014, approximately 16 million acres of public lands had been

withdrawn and reserved for military uses.37

The Sikes Act stipulates that for implementation and enforcement of INRMPs, DOD is to

prioritize entering into “contracts for the procurement of such implementation and enforcement

services with Federal and State agencies having responsibility for the conservation or

management of fish or wildlife.”38 The Sikes Act provides the Secretary of Defense with

enforcement authority for “all Federal laws relating to the management of natural resources on

Federal lands on military installations in the United States.”39

Required Content for Integrated Natural Resources Management

Plans

The Sikes Act requires INRMPs to be consistent with the military installation’s activities to

ensure the preparedness of the armed forces and not result in the net loss of the installation’s

capability to support its mission.40 Congress mandated that INRMPs shall provide for

•

fish and wildlife management, land management, and fish- and wildlife-oriented

recreation;

33 16 U.S.C. §670a(a)(3).

34 16 U.S.C. §670a(2). Although Integrated Natural Resources Management Plans (INRMPs) are required, mutual

agreement of DOD, FWS, and state agencies is required by statute only for parts of INRMPs “concerning conservation,

protection, and management of fish and wildlife resources.” FWS policy guidance on INRMP coordination notes, “the

overall goal of the parties is to reach agreement on the entire INRMP; however, it is a requirement that INRMPs reflect

mutual agreement on the conservation, protection, and management of fish and wildlife resources.” See FWS,

Guidelines for Coordination on Integrated Natural Resource Management Plans, June 2015, p. 9,

https://www.fws.gov/sites/default/files/documents/INRMP-Guidelines-with-Pollinator-Addendum-and-Disclaimer.pdf

(hereinafter FWS, Guidelines for Coordination on INRMPs).

35 DOD Instruction 4715.03, p. 13, notes the “National Oceanic and Atmospheric Administration (NOAA) Fisheries is

not referenced in the Sikes Act, and therefore not required to review INRMPs for operation and effect, but their

participation is recommended, when appropriate.” For further information on stakeholder engagement policies, see

Secretary of the Air Force, Department of the Air Force Manual 32-7003: Environmental Conservation, June 26, 2024,

p. 57, https://static.e-publishing.af.mil/production/1/af_a4/publication/dafman32-7003/dafman32-7003.pdf (hereinafter

Secretary of the Air Force, Air Force Manual 32-7003).

36 Secretary of the Air Force, Air Force Manual 32-7003, p. 57.

37 Statement of Ned Farquhar, Deputy Assistant Secretary, Land and Minerals Management, Department of the Interior

in U.S. Congress, House Natural Resources Committee, H.R.4253, Bureau of Land Management Withdrawn Military

Lands Efficiency and Savings Act, hearing, 113th Cong., 2nd sess., March 25, 2014, https://www.doi.gov/ocl/hearings/

113/hr4253_032514.

38 16 U.S.C. §670a(d).

39 16 U.S.C. §670e–1.

40 16 U.S.C. §670a(b).

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•

•

•

•

•

•

•

•

•

fish and wildlife habitat enhancement or modifications;

wetland protection, enhancement, and restoration, where necessary for support of

fish, wildlife, or plants;

integration of, and consistency among, the various activities conducted under the

plan;

establishment of specific natural resource management goals and objectives and

time frames for proposed action;

sustainable use by the public of natural resources to the extent that the use is not

inconsistent with the needs of fish and wildlife resources;

public access to the installation that is necessary or appropriate for the use of

natural resources, subject to requirements necessary to ensure safety and military

security;

enforcement of applicable natural resource laws and regulations;

no net loss in the capability of installation lands to support the military mission of

the installation; and

such other activities as the Secretary of the Army, Navy, or Air Force determines

appropriate.41

In the James M. Inhofe National Defense Authorization Act for Fiscal Year 2023 (P.L. 117-263),

Congress further directed the Secretary of Defense (in consultation with the Secretary of the

Interior) to incorporate management, control, and eradication of invasive species in INRMPs.42

The law directs that focus is to be on invasive species that “may cause harm to military readiness,

the environment, or human health and safety.”43

The Sikes Act includes specific language outlining the treatment of migratory game birds and

outdoor recreation in INRMPs. The law authorizes the Secretary of Defense, in cooperation with

the Secretary of the Interior and the appropriate state agency, to conduct activities to conserve,

restore, and manage migratory game birds on military installations, in accordance with mutually

approved INRMPs.44 The Secretary of Defense also is authorized to issue special migratory bird

hunting permits and collect associated fees.45

The Sikes Act authorizes the Secretary Defense to develop, enhance, operate, and maintain public

outdoor recreation resources at military installations in accordance with INRMPs. Military

installations may accept property donations (real or personal) and may volunteer assistance in

connection with public outdoor recreation programs and facilities.46 In the Strom Thurmond

National Defense Authorization Act for Fiscal Year 1999 (P.L. 105-261), Congress directed the

Secretary of Defense to ensure, to the extent practicable, that public outdoor recreation

opportunities at military installations also provide access to persons with disabilities “when

41 16 U.S.C. §670a(b).

42 This provision expanded a prior pilot program to incorporate invasive species management in INRMPs for military

installations on Guam.

43 16 U.S.C. §670a(g).

44 16 U.S.C. §670b.

45 As outlined at 16 U.S.C. §670b(b), possession of this permit does not relieve individuals of additional permitting

requirements under the Migratory Bird Hunting Stamp Act (16 U.S.C. §§718 et seq.) or applicable requirements under

state law (as set forth at 10 U.S.C. §2671).

46 16 U.S.C. §670c(c).

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topographic, vegetative, and water resources permit access for such persons without substantial

modification to the natural environment.”47

Integrated Natural Resources Management Plan Approval Process

and Reporting Requirements

By law, DOD and other signatories are to formally review INRMPs at least every five years.48

DOD also has required installations to annually review INRMPs in coordination with

stakeholders to determine if updates are necessary and to establish work plans for implementing

activities pursuant to INRMPs.49 By law, DOD is to ensure sufficient numbers of professional

staff administer Sikes Act responsibilities, including preparation and implementation of

INRMPs.50

FWS implements Sikes Act activities through its Ecological Services and Fish and Aquatic

Conservation program field offices. These field offices are responsible for coordinating INRMP

development.51 Military installations request FWS’s participation by informing the applicable

FWS field office of intent to prepare or revise an INRMP.52

INRMPs are deemed compliant when they have been reviewed and approved within a five-year

period by all signatories to the plan.53 In FY2023, DOD managed 341 INRMPs, of which 84%

were considered compliant.54 Not later than March 1 of each year, the Secretary of Defense is to

review the extent to which DOD has prepared and implemented INRMPs and to submit a report

on the findings of the review to Congress.55 Each report is to include (1) the number of INRMPs

in effect in the year, including the date on which each plan was finalized or most recently revised;

(2) the amount of funding spent on conservation activities conducted pursuant to INRMPs in the

year covered by the report; and (3) an assessment of the extent to which the INRMPs comply

with the Sikes Act.56

Similarly, not later than March 1 of each year, the Secretary of the Interior is to submit a report to

Congress on the amount of funding expended by the Department of the Interior and state fish and

wildlife agencies on conservation activities conducted in accordance with INRMPs.57

Interaction of the Sikes Act with the Endangered Species Act

One of the primary purposes of the ESA is to provide for a nationwide framework for the

conservation of ecosystems and habitat on which endangered and threatened species depend.58

The ESA directs the Secretary of the Interior (acting through FWS) and the Secretary of

47 16 U.S.C. §670c.

48 16 U.S.C. §670a(b)(2).

49 Secretary of the Air Force, Air Force Manual 32-7003, pp. 59-60.

50 16 U.S.C. §670e-2.

51 FWS, Guidelines for Coordination on INRMPs, p. 10.

52 FWS, Guidelines for Coordination on INRMPs, p. 23.

53 DOD, Defense Environmental Programs Annual Report FY2023, p. 6.

54 DOD, Defense Environmental Programs Annual Report FY2023, p. 6.

55 16 U.S.C. §670a(f).

56 16 U.S.C. §670a(f)(1).

57 16 U.S.C. §670a(f)(2).

58 16 U.S.C. §1531(c).

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Commerce (acting through NMFS) to designate critical habitat for listed species and ensure

federal actions do not adversely impact critical habitat.59 The ESA defines critical habitat to

include geographic areas that FWS or NMFS deems essential to the species’ conservation. These

areas may or may not be occupied by the species at the time of listing.60

In P.L. 107-314, Congress exempted DOD lands from designation as critical habitat under the

ESA, provided that the lands were covered by an approved INRMP that includes conservation

measures beneficial for endangered species.61 The conference report that accompanied P.L. 107314 noted that “the conferees are concerned that future designations of critical habitat on military

training ranges could have an adverse impact on the military’s readiness capabilities.”62

In the National Defense Authorization Act for Fiscal Year 2012 (P.L. 112-81), Congress amended

the Sikes Act to authorize the Secretary of Defense to develop and implement INRMPs for stateowned National Guard facilities, through coordination with the state governor and FWS.63 These

state-owned National Guard installations include “land owned and operated by a State when such

land is used for training the National Guard pursuant to ... [32 U.S.C. §§501-510], with funds

provided by the Secretary of Defense or the Secretary of a military department.”64 Exemptions

from critical habitat designation under ESA are applicable to National Guard installations with

approved INRMPs.

The Sikes Act planning process is different from the designation of critical habitat process under

the ESA.65 As mandated by Congress in P.L. 107-314, military installations with finalized

INRMPs are exempt from critical habitat designations under the ESA, if the Secretary of the

Interior determines in writing that the INRMP provides benefits to the species.66 INRMPs are to

meet military objectives as first priority and conservation objectives as a second priority. The use

of INRMPs as an alternative to critical habitat designations has been the subject of debate, as

some stakeholders see the arrangement as a necessary or preferable concession to military

readiness needs and some do not.67

Cooperative Agreements and Partnerships

The Sikes Act authorizes DOD to enter into cooperative agreements with states, local

governments, Indian tribes, nongovernmental organizations, and individuals, as well as

interagency agreements with other federal departments and agencies, for maintenance and

improvement of natural resources on and off military and state-owned national guard installations

59 16 U.S.C. §1533(a)(3)(A).

60 16 U.S.C. §1532(5).

61 16 U.S.C. §1533(a)(3)(B).

62 U.S. Congress, House of Representatives, National Defense Authorization Act for Fiscal Year 2003, conference

report to accompany H.R. 4546, 107th Cong., 2nd sess., H.Rept. 107-772, November 12, 2002, pp. 632-633.

63 16 U.S.C. §670a(a).

64 16 U.S.C. §670(3).

65 For more information on the designation of critical habitat under the ESA, see CRS Report R46677, The Endangered

Species Act: Overview and Implementation, by Pervaze A. Sheikh and Erin H. Ward.

66 16 U.S.C. §1533(a)(3)(B)(i) notes, “The Secretary [of the Interior] shall not designate as critical habitat any lands or

other geographical areas owned or controlled by the Department of Defense, or designated for its use, that are subject

to an integrated natural resources management plan prepared under section 670a of this title, if the Secretary determines

in writing that such plan provides a benefit to the species for which critical habitat is proposed for designation.”

67 For a brief summarization of various views related to DOD’s exemptions from environmental laws, see Cranston,

“U.S. Military’s Environmental Protection Efforts,” pp. 1038-1041.

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in furtherance of INRMPs.68 Congress has gradually expanded DOD’s authority to work

cooperatively with federal and nonfederal partners under the Sikes Act.

In 1989, Congress passed the National Defense Authorization Act for Fiscal Years 1990 and 1991

(P.L. 101-189). The law provided the Secretary of Defense with authority to enter into

cooperative agreements with states, local governments, nongovernmental organizations, and

individuals to maintain or improve natural resources on military installations.69 Under P.L. 10585, Congress provided DOD with authority to obligate funds under cooperative agreements

across fiscal years.70

The Duncan Hunter National Defense Authorization Act for Fiscal Year 2009 (P.L. 110-417)

expanded the authority of Secretaries of military departments to enter into cooperative

agreements with states, local governments, nongovernmental organizations, and individuals to

provide for maintenance and improvement of natural resources located off a military installation

if the cooperative agreement’s purpose is “to relieve or eliminate current or anticipated challenges

that could restrict, impede, or otherwise interfere with, whether directly or indirectly, current or

anticipated military activities.”71 The following year, in the National Defense Authorization Act

for Fiscal Year 2010 (P.L. 111-84), Congress further amended this authority to include

interagency agreements with other federal departments and agencies for land management

activities on and off military installations.72 In the National Defense Authorization Act for Fiscal

Year 2013 (P.L. 112-239), Congress added Indian Tribes to the list of entities with which the

Secretary of Defense is authorized to enter into cooperative agreements to maintain or improve

natural resources on or off military installations.73

Partnership arrangements are designed to accomplish various objectives, including managing

species listed under the ESA, conserving and restoring habitat, and reducing potential

encroachment and interference with military operations by promoting compatible uses of land on

neighboring properties.74 DOD has indicated that cooperative arrangements entered pursuant to

the Sikes Act can provide a cost-effective alternative to the acquisition of real property interests

to prevent encroachment and preserve habitat surrounding military installations. Under the Sikes

Act, DOD may enter into agreements with landowners to manage lands for certain purposes over

a period of time. This flexible arrangement can be less expensive than acquiring conservation

easements pursuant to other authorities.75

DOD enters into cooperative agreements to support both broad and specific initiatives. For

instance, DOD, FWS, and the Association of Fish and Wildlife Agencies signed a memorandum

of understanding (MOU) in 2024 to enhance cooperation in management of natural resources on

68 16 U.S.C. §670c-1.

69 16 U.S.C. §670c–1.

70 Under 16 U.S.C. §670c–1(b), DOD may obligate funds appropriated in a fiscal year to cooperative or interagency

agreements over an 18-month period beginning in that fiscal year, regardless of whether the agreement crosses into

another fiscal year.

71 16 U.S.C. §670c–1(a)(2).

72 16 U.S.C. §670c–1.

73 For the purposes of the Sikes Act (16 U.S.C. §670(6)), Congress defined Indian Tribes to mean “any Indian tribe,

band, nation, or other organized group or community, including any Alaska Native village or regional or village

corporation as defined in or established pursuant to the Alaska Native Claims Settlement Act (43 U.S.C. §§1601 et

seq.), which is recognized as eligible for the special programs and services provided by the United States to Indians

because of their status as Indians.”

74 Cranston, “U.S. Military’s Environmental Protection Efforts,” pp. 1054-1055.

75 John C. Cruden et al., “The Local Environment at the U.S. Department of Defense,” Environmental Law Reporter

News & Analysis vol. 43, no. 12 (December 2013), pp. 11060-11061.

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military lands broadly.76 This MOU built upon a prior agreement signed in 2013.77 In other

circumstances, DOD enters into agreements to support initiatives at specific military installations

pursuant to INRMPs.

Funding for Sikes Act Implementation

Funding for Sikes Act implementation comes from several sources, including appropriations and

fees. DOD uses appropriations from its Operations and Maintenance (O&M) accounts to fund

environmental activities, including those mandated under the Sikes Act.78 FWS uses

appropriations across several of its accounts (including Fish and Aquatic Conservation and

Ecological Services) to support Sikes Act responsibilities.79

Congress amended the Sikes Act to include authorizations of appropriations for the Secretary of

Defense and the Secretary of the Interior in 1968 and 1974, respectively.80 Congress has

reauthorized these appropriations numerous times, most recently through FY2019 by the National

Defense Authorization Act for Fiscal Year 2014 (P.L. 113-66).81 DOD and DOI rarely have

requested funding specifically for implementing the Sikes Act, instead allocating funds requested

under broader appropriations authorities for Sikes Act responsibilities.82 As such, Congress

typically does not provide appropriations for the Sikes Act through a dedicated account.83

Under the Sikes Act, DOD installations may collect hunting and fishing permit fees. Any

collections are to be used only on the installation where they were collected and only for

conservation activities.84 DOD also has authority to use revenue collected from the sale of forest

76 Memorandum of Understanding Between the U.S. Department of Defense and the U.S. Fish and Wildlife Service

and the Association of Fish and Wildlife Agencies for Cooperative and Integrated Natural Resources Management,

October 2024, https://web.archive.org/web/20241209112734/https://www.denix.osd.mil/nr/denix-files/sites/38/2024/

10/Final-Sikes-Act-MOU-Signed-October-2024.pdf.

77 Memorandum of Understanding Between the U.S. Department of Defense and the U.S. Fish and Wildlife Service

and the Association of Fish and Wildlife Agencies for a Cooperative Integrated Natural Resources Management

Program on Military Installations, July 2013, https://www.fishwildlife.org/application/files/6216/9634/7890/03_SikesTripartite-MOU.pdf.

78 Office of the Under Secretary of Defense (Comptroller)/Chief Financial Officer, Defense Operations and

Maintenance Overview: United States Department of Defense Fiscal Year 2025 Budget Request, March 2024, p. 43,

https://comptroller.defense.gov/Portals/45/Documents/defbudget/FY2025/FY2025_OM_Overview.pdf; U.S. Congress,

House Armed Services Committee, Hearing on H.R. 1202 to Authorize Appropriations to Carry Out Conservation

Programs on Military Reservations and Public Lands During Fiscal Years 1986, 1987, and 1988, committee print, 99th

Cong., 1st sess., HASC print no. 99-7, June 18, 1985, p. 24.

79 FWS uses funding to provide technical assistance to develop and review INRMPs and to implement INRMP-related

actions (including fish and wildlife population assessments and invasive species control). Funding also covers

consultations pursuant to the ESA. Testimony of Dan Ashe, Deputy Director, U.S. Fish and Wildlife Service,

Department of the Interior in U.S. Congress, House Natural Resources Committee, The Sikes Act Amendments Act of

2010, hearing on H.R.5284, May 25, 2010, https://www.fws.gov/testimony/hr-5284-sikes-act-amendments-act.

80 16 U.S.C. §670f(b) and §670f(c).

81 P.L. 113-66, §313.

82 In 2014, the House Natural Resources Committee noted, “neither DOD nor FWS receives a direct appropriation for

[the Sikes Act] program. Instead, the nearly $60 million that has been spent during the past ten fiscal years in support

of Sikes Act activities has been consistently funded through general administrative funds.” U.S. Congress, House

Natural Resources Committee, Sikes Act Cooperative Agreements, report to accompany H.R. 4309, 113th Congress, 2nd

sess., H.Rept. 113-647, Pt. 1, December 8, 2014, p. 2.

83 U.S. Congress, House Natural Resources Committee, Sikes Act Reauthorization Act of 2013, report to accompany

H.R. 910, 113th Cong., 1st sess., H.Rept. 113-119, Pt 1, June 24, 2013, pp. 1, 5 (hereinafter House Natural Resources

Committee, Sikes Act Reauthorization Act of 2013, H.Rept. 113-119, Pt. 1).

84 DOD Instruction 4715.03, pp. 20-21.

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products (e.g., timber harvesting) and lease payments for agriculture and grazing on military

lands for conservation activities.85 In the event that the military closes installations, DOD is

authorized to transfer any remaining revenues from fees collected pursuant to outdoor recreation

activities under the Sikes Act to other another active installation for conservation purposes.86

It is difficult to ascertain exactly how much funding DOD and DOI expend on Sikes Act

responsibilities. DOD reports on expenditures under the act are publicly available and comingle

funds expended pursuant to other environmental programs and authorities.87 In FY2023 (the most

recent funding year data available), Congress provided $636.5 million to DOD’s O&M account

for environmental conservation activities.88 This funding supports Sikes Act implementation and

other environmental activities.89

Considerations for Congress

Congress might consider several aspects of the implementation of the Sikes Act through

oversight, appropriations, and legislation. Congress may evaluate whether DOD activities are

accomplishing the act’s goals and, if not, whether the level of funding for implementing the Sikes

Act is sufficient. DOD and DOI have rarely requested appropriations through the budget authority

of the Sikes Act; instead, the agencies typically use funding from broader accounts and authorities

to fund activities under the Sikes Act.90 As such, it is difficult to ascertain exactly how much

funding federal agencies are expending pursuant to the Sikes Act. This situation is not unique to

the Sikes Act, as expenditures pursuant to some other conservation authorities (e.g., ESA) are not

clearly specified in all agencies.

Further, Congress may continue to review the extent to which, if at all, complying with

environmental statutes on DOD lands affects military readiness.91 In the 118th and 119th

Congresses, some Members have introduced bills to further exclude military installations from

critical habitat designations. For instance, as introduced in the 119th Congress, H.R. 65 would

eliminate the requirement for the Secretary of Defense to consult with the Secretary of the

Interior to ensure proposed actions are not likely to jeopardize listed species or adversely impact

critical habitat pursuant to Section 7(a)(2) of the ESA, regardless of whether the military

installation is subject to an approved INRMP.92 In response to proposals of this nature, some

stakeholders have argued that DOD has not sufficiently demonstrated that ESA compliance

85 10 U.S.C. §2667.

86 16 U.S.C. §670a(b)(3)(B).

87 DOD’s annual reports to Congress are available at https://www.denix.osd.mil/arc/.

88 This total does not include funding for classified programs. Office of the Under Secretary of Defense

(Comptroller)/Chief Financial Officer, Defense Operations and Maintenance Overview: United States Department of

Defense Fiscal Year 2025 Budget Request, (March 2024), pp. 43-44.

89 For example, O&M funding also is allocated to the Readiness and Environmental Protection Integration (REPI)

Program, which provides funding to installations to enter into cost-sharing agreements with federal agencies, state and

local government, and private partners to mitigate land-use conflicts near military bases, address environmental

restrictions that may impact military activities, and increase resilience. See DOD, “About the DOD REPI Program,”

https://www.repi.mil/.

90 House Natural Resources Committee, Sikes Act Reauthorization Act of 2013, H.Rept. 113-119, Pt 1, pp. 1, 5.

91 For background on DOD’s exemptions from environmental laws, see Cranston, “U.S. Military’s Environmental

Protection Efforts,” pp. 1038-1041. Additional context on environmental exemptions for military training activities is

available in Government Accountability Office (GAO), Military Training: Compliance with Environmental Laws

Affects Some Training Activities, But DOD Has Not Made a Sound Business Case for Additional Exemptions, GAO-08407, March 2008, https://www.gao.gov/products/gao-08-407.

92 H.R. 65 (Armed Forces Endangered Species Exemption Act).

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hinders the Armed Services’ ability to function and, therefore, that DOD does not need further

exemption from the ESA.93

In recent years, Congress has amended the Sikes Act to direct DOD to undertake additional

conservation-related activities on military installations. For instance, in P.L. 117-263, Congress

amended the Sikes Act to expand the purposes of conservation programs under the act to provide

for the use of nature-based solutions to maintain or improve resilience at military installations.94

In addition, Congress mandated that INRMPs incorporate management, control, and eradication

of invasive species on DOD lands.95 Congress may consider how environmental conditions on

military lands might impact readiness and whether addressing those changes is a function that

should be addressed in INRMPs.

Author Information

Eric P. Nardi

Analyst in Natural Resources Policy

Disclaimer

This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan

shared staff to congressional committees and Members of Congress. It operates solely at the behest of and

under the direction of Congress. Information in a CRS Report should not be relied upon for purposes other

than public understanding of information that has been provided by CRS to Members of Congress in

connection with CRS’s institutional role. CRS Reports, as a work of the United States Government, are not

subject to copyright protection in the United States. Any CRS Report may be reproduced and distributed in

its entirety without permission from CRS. However, as a CRS Report may include copyrighted images or

material from a third party, you may need to obtain the permission of the copyright holder if you wish to

copy or otherwise use copyrighted material.

93 For example, see, Defenders of Wildlife, “The 119th Congress: Playing Politics with Extinction,”

https://defenders.org/119th-congress-playing-politics-extinction; Earthjustice et al., “NDAA-Please Vote No on 23.

Biggs Anti-ESA Amendment #441,” June 12, 2024, https://earthjustice.org/wp-content/uploads/2024/06/please-voteno-on-biggs-anti-esa-amendment-to-ndaa-1.pdf.

94 16 U.S.C. §670a(3).

95 16 U.S.C. §670a(g).

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