Grizzly Bears and the Endangered Species Act

June 28, 2024 R48116

Grizzly Bears and the Endangered Species Act
June 28, 2024
Grizzly bears (Ursus arctos horribilis) are an iconic species that once roamed large swaths of the
United States, Canada, and Mexico. In the United States, grizzly bear populations declined in the
Erin H. Ward
19th century; grizzly bears now exist in several populations in the lower 48 states of the United
Coordinator of Research
States and throughout Alaska. Grizzly bears are listed as threatened under the Endangered
Planning/ALD
Species Act (ESA) (16 U.S.C. §§1531-1544) in the lower 48 states, which gives them certain

statutory protections.
Pervaze A. Sheikh
Specialist in Natural
Congress is interested in the status of grizzly bears under the ESA because of the species’ high
Resources Policy
profile and constituents’ competing concerns. For example, some stakeholders assert that grizzly

bears should be removed (delisted) from the ESA; they contend that grizzly bear populations are
recovered and do not face the threat of extinction in the future. These stakeholders support state
Benjamin M. Barczewski
management of grizzly bears rather than federal management through the ESA. Some other
Legislative Attorney
stakeholders support keeping grizzly bears listed under the ESA, which they contend is necessary

to prevent the extinction of the species and facilitate its recovery. Some stakeholders also assert
that if grizzly bears were delisted, state management of grizzly bears would be detrimental to the

species.
Under the ESA, grizzly bears are protected through a rule that generally prohibits the import, commercial export, commercial
transportation, sale, or take of grizzly bears in the lower 48 states. The rule also prohibits certain activities with unlawfully
taken grizzly bears. The rule provides for certain exceptions to the prohibited acts, notably that federal and state employees
are allowed to pursue, capture, collect, and import grizzly bears and to possess, move, or export unlawfully taken grizzly
bears, so long as those activities are for scientific or educational purposes. The regulations also allow grizzly bears to be
taken in self-defense or in defense of others or to be removed if they are threatening human safety or livestock, so long as
certain conditions are met.
The U.S. Fish and Wildlife Service (FWS) has created a recovery plan for the conservation and survival of grizzly bears. The
latest iteration of this plan was published in 1993, and it identified five recovery zones in the lower 48 states with known
populations of grizzly bears: (1) the Northern Continental Divide Ecosystem (NCDE) in Montana, (2) the Cabinet-Yaak
Ecosystem (CYE) in Montana, (3) the Selkirk Ecosystem (SE) in Idaho and Washington, (4) the North Cascades Ecosystem
(NCE) in Washington, and (5) the Greater Yellowstone Ecosystem (GYE) in Montana and Wyoming. A potential sixth
region in the Bitterroot Ecosystem in Idaho also was identified with sufficient habitat for grizzly bears and later became a
recovery zone. The plan stated an intent to delist individual populations as they achieved recovery.
FWS has attempted to designate the GYE grizzly bear population as a distinct population segment (DPS) and delist that DPS
on two occasions. (A DPS is a population of a species that must be discrete from the remainder of the species and significant
to that species.) In 2007 and 2017, FWS published final rules designating the GYE population as a DPS and delisting it; both
attempts resulted in litigation. Courts vacated each of the rules, and the GYE population remains listed as threatened under
the ESA. On February 6, 2023, FWS found that petitions to delist grizzly bears in the NCDE and GYE populations had
presented sufficient information to indicate that delisting may be warranted. Accordingly, FWS announced it was initiating a
status review of the NCDE and GYE populations to determine whether delisting is warranted.
The 118th Congress has held oversight hearings addressing the listing of grizzly bears and introduced several bills that would
direct the Secretary of the Interior to delist grizzly bears (none have been enacted). Most of the legislative debate in the 118th
Congress centers on the listing status of the GYE and NCDE populations of grizzly bears and whether grizzly bears in the
lower 48 states should be listed under the ESA. For example, Congress is considering H.R. 1419 and H.R. 1245, which
would direct the Secretary of the Interior to issue a final rule to delist the NCDE grizzly bear population and reissue a final
rule to delist the GYE population. Both bills also would preclude judicial review of the listing rules. In considering these and
other measures addressing grizzly bears, Congress may consider certain issues, including (1) state versus federal management
of grizzly bear populations, (2) conflicts between bears and humans and livestock, and (3) science and the conservation of
grizzly bears.

Congressional Research Service

Grizzly Bears and the Endangered Species Act

Introduction
Grizzly bears (Ursus arctos horribilis) are an iconic apex predator that once roamed large swaths
of the United States, Canada, and parts of Mexico.1 In the United States, grizzly bears were
historically one contiguous population with an estimated 50,000 bears prior to 1800.2 This
population declined in the 19th century following the expansion of settlers in the western United
States, Mexico, and Canada. Settlers viewed grizzly bears as a threat to human settlement and
safety, and bears were widely hunted wherever they were found.3 In some cases, hunters were
compensated for killing grizzly bears by government-sponsored bounty programs. Grizzly bear
populations also declined due to the conversion of their habitat to agricultural uses. Grizzly bears
are currently separated into several populations in the contiguous 48 states of the United States
and are considered locally extinct in Mexico and the central and southwestern United States,
according to scientists.4
Grizzly bears have been listed as threatened under the Endangered Species Act (ESA) in the
contiguous 48 states since 1975,5 which gives the species certain statutory protections.
Stakeholders have long debated whether the species should remain listed or should be delisted
(i.e., taken off the list of endangered and threatened species). Some stakeholders assert that
grizzly bears should be removed from the list; they contend that grizzly bear populations are
recovered and do not face the threat of extinction in the future. Some of these stakeholders also
contend that expanding grizzly bear populations are leading to more livestock losses and human-
bear conflicts that would be easier to manage under state law than under the ESA.6 They argue
that delisting grizzly bears would allow states to manage populations with greater flexibility than
the federal government.7 In contrast, some stakeholders support continued listing and contend that
it is necessary to prevent the extinction of the species.8 They argue that keeping the grizzly bear
listed under the ESA will lead to the conservation and recovery of the species.9 Some
stakeholders assert that if grizzly bears were delisted, state management of the species would be
inadequate and potentially detrimental to the species.10

1 U.S. Fish and Wildlife Service (FWS), Environmental Conservation Online System (ECOS), “Grizzly Bear (Urus
arctos horribilis),” https://ecos.fws.gov/ecp/species/7642https://ecos.fws.gov/ecp/species/7642 (hereinafter cited as
ECOS).
2 Ibid.
3 Ibid.
4 Ibid.
5 16 U.S.C. §§1531-1544.
6 National Cattlemen’s Beef Association, “FWS Keeps ESA Status for Grizzly Bears Despite Recovered Populations,”
press release, March 31, 2021, https://www.ncba.org/ncba-news/news-releases/news/details/26273/fws-keeps-esa-
status-for-grizzly-bears-despite-recovered-populationshttps://www.ncba.org/ncba-news/news-releases/news/details/
26273/fws-keeps-esa-status-for-grizzly-bears-despite-recovered-populations.
7 Mark Gordon, Governor of Wyoming, “Petition: To Establish the Greater Yellowstone Ecosystem (GYE) Grizzly
Bear (Ursus arctos horribilis) Distinct Population Segment (DPS) and Remove the GYE Grizzly Bear DPS from the
Federal List of Endangered and Threatened Wildlife,” State of Wyoming, Office of the Governor, January 10, 2022,
https://wyofile.com/wp-content/uploads/2022/01/GYE-Grizzly-Bear-Petition.pdfhttps://wyofile.com/wp-content/
uploads/2022/01/GYE-Grizzly-Bear-Petition.pdf (hereinafter cited as Gordon, Petition).
8 Defenders of Wildlife, “U.S. Fish and Wildlife Service Announces Status Review of Grizzly Bears,” press release,
February 3, 2023, https://defenders.org/newsroom/us-fish-and-wildlife-service-announces-status-review-of-grizzly-
bearshttps://defenders.org/newsroom/us-fish-and-wildlife-service-announces-status-review-of-grizzly-bears.
9 Ibid.
10 Center for Biological Diversity, “State Efforts to Remove Federal Grizzly Protections Move Forward,” press release,
(continued...)
Congressional Research Service

1

Grizzly Bears and the Endangered Species Act

In oversight hearings, Members of Congress have addressed varying perspectives on the grizzly
bear’s listing under the ESA, the grizzly bear’s population status, and the effects of grizzly bears
on livestock. Members also have introduced related legislation in the 118th Congress. For
example, S. 2571 would direct the Secretary of the Interior to remove all listings of grizzly bears
under the ESA, and H.R. 1419 would direct the Secretary of the Interior to delist a particular
population of grizzly bears in Montana under the ESA.
This report provides background on the status and biology of grizzly bears, a history of the
species’ listing under the ESA, an overview of litigation surrounding listing decisions, and
considerations for Congress on issues related to listing grizzly bears under the ESA.
Biology, Population, and Range of Grizzly Bears
The species “brown bear” (Ursus arctos) comprises several subspecies, with disparate
populations distributed across North America, Europe, and Asia.11 The grizzly bear (Ursus arctos
horribilis) is a subspecies of the brown bear.12 In the conterminous United States, there are
isolated populations of grizzly bears in Washington, Idaho, Montana, and Wyoming.13 Grizzly
bears live until their mid- to late 20s in the wild, with multiple opportunities for reproduction in a
lifetime.14 They have one of the slowest reproductive rates among terrestrial animals, which
influences the species’ status and population trends.15 They generally mate between May and July
and hibernate for four to six months in dens over the winter.16 It takes five to six years for female
grizzly bears to reach reproductive age, and, due to small litter sizes (generally two cubs) and cub
mortality rates, it can take a female grizzly bear 10-15 years to replace itself in the population.17
This slow replacement rate limits the potential for rapid population growth and makes population
growth rates sensitive to female mortality.18
Grizzly bears occupy multiple habitat types that vary by water, vegetative cover, den sites, and
food.19 Available habitat for grizzly bears is influenced by human activities (e.g., settlements,
vehicles, noise). According to the U.S. Fish and Wildlife Service (FWS), grizzly bears seek open
areas for feeding sites with vegetative cover nearby to conceal themselves and create bedding
areas.20

February 3, 2023, https://biologicaldiversity.org/w/news/press-releases/state-efforts-to-remove-federal-grizzly-
protections-move-forward-2023-02-03/https://biologicaldiversity.org/w/news/press-releases/state-efforts-to-remove-
federal-grizzly-protections-move-forward-2023-02-03/.
11 FWS, “Grizzly Bear,” https://www.fws.gov/species/grizzly-bear-ursus-arctos-horribilishttps://www.fws.gov/species/
grizzly-bear-ursus-arctos-horribilis.
12 Ibid.
13 Ibid.
14 Charles C. Schwartz et al., “Temporal, Spatial, and Environmental Influences on the Demographics of Grizzly Bears
in the Greater Yellowstone Ecosystem,” Journal of Wildlife Monographs, vol. 161, no. 1 (December 13, 2010;
hereinafter cited as Schwartz et al., “Temporal, Spatial, and Environmental Influences”).
15 FWS, Species Status Assessment for the Grizzly Bear (Ursus arctos horribilis) in the Lower-48 States, January 2022,
https://ecos.fws.gov/ServCat/DownloadFile/213247 (hereinafter cited as FWS, Species Status Assessment).
16 Ibid.
17 Ibid.
18 Schwartz et al., “Temporal, Spatial, and Environmental Influences.”
19 Ibid.
20 FWS, Species Status Assessment.
Congressional Research Service

2

Grizzly Bears and the Endangered Species Act

Grizzly bears are large animals, with males generally weighing from 400 to 800 pounds.21 Grizzly
bears support this body mass with a diverse omnivorous diet that includes up to 260 species of
plants and animals.22 Wild sources of food for grizzly bears include berries (e.g., blueberries,
bearberries), roots, plant bulbs, whitebark pine seeds, rodents, moose, elk, mountain goats, and
mountain sheep.23 Grizzly bears are opportunistic feeders that shift their diet throughout the year
based on food availability and explore several potential food sources, including anthropogenic
sources such as livestock, crops (e.g., grain, corn, melons), and garbage.24 This opportunistic
behavior sometimes leads to conflicts with humans, especially around ranches, farms, and areas
with large amounts of food waste.25 For example, some studies suggest that higher bear densities
are associated with higher depredation rates of cattle and sheep.26
Figure 1. Resident and Historic Grizzly Bear Range

Source: Interagency Grizzly Bear Committee, “About Us,” https://igbconline.org/about-us/https://igbconline.org/
about-us/.
Notes: Resident range is the approximate area where grizzly bears are currently found.

21 Ibid.
22 ECOS.
23 North American Bear Center, “Brown and Grizzly Bear Facts,” https://bear.org/brown-grizzly-bear-facts/.
24 Ibid.
25 Ibid.
26 ECOS.
Congressional Research Service

3

link to page 6 link to page 7 Grizzly Bears and the Endangered Species Act

The historical range of grizzly bears covered most of the western half of the United States,
western Canada, north-central Mexico, and Alaska, as shown in Figure 1. Westward expansion of
settlers and the associated habitat alteration and hunting led to a significant reduction in the range
of grizzly bears in the United States, Canada, and Mexico, according to FWS.27 In the lower 48
states, the range of grizzly bears was reduced to 2% of its estimated historical size by the 1930s.28
This reduction paralleled a decrease in grizzly bear population size from approximately 50,000
bears prior to 1800 to between 700 and 800 bears in the lower 48 states when the grizzly bear was
listed under the ESA in 1975.29 Most of these bears were in national parks and wilderness areas in
Washington, Idaho, Montana, and Wyoming.30
Grizzly bear population sizes and the extent of their range in some areas have increased since the
ESA listing. As of 2021, there were an estimated 1,926 grizzly bears in the lower 48 states,
primarily in Washington, Idaho, Montana, and Wyoming.31 In Alaska and Canada, there are an
estimated 55,000 grizzly bears.32 The range of grizzly bears in the lower 48 states has expanded
since grizzly bears were listed and now covers approximately 6% of their estimated historical
range.33 Table 1 contains the population estimates in six recovery zones in the lower 48 states,
identified by FWS, that support or may support grizzly bear populations. These ecosystems
include (1) the Northern Continental Divide Ecosystem (NCDE) in Montana, (2) the Cabinet-
Yaak Ecosystem (CYE) in Montana, (3) the Selkirk Ecosystem (SE) in Idaho and Washington, (4)
the North Cascades Ecosystem (NCE) in Washington, (5) the Greater Yellowstone Ecosystem
(GYE) in Montana and Wyoming, and (6) the Bitterroot Ecosystem (BE) in Idaho.
Table 1. Population Estimates of Grizzly Bears in Six Recovery
Zones in the Lower 48 States as of 2021
Ecosystem (State)
Estimated Number of Bears
Northern Continental Divide (MT)
1,095
Greater Yellowstone (MT, WY)
727
Cabinet-Yaak (MT)
60
Selkirk (ID, WA)
Minimum of 44 in U.S. portion
Bitterroot (ID)
No known population
North Cascades (WA)
No known population
Source: U.S. Fish and Wildlife Service (FWS), Upper Colorado Region, Grizzly Bear in the Lower-48 States (Ursus
arctos horribilis)—5-Year Status Review: Summary and Evaluation, March 2021, https://ecos.fws.gov/docs/tess/
species_nonpublish/942.pdfhttps://ecos.fws.gov/docs/tess/species_nonpublish/942.pdf; Frank T. Van Manen et al.,
Yellowstone Grizzly Bear Investigations 2022: Annual Report of the Interagency Grizzly Bear Study Team, U.S.
Geological Survey, 2023, https://igbconline.org/wp-content/uploads/2023/09/Yellowstone-Grizzly-Bear-
Investigations-2022-IGBST-Annual-Report.pdfhttps://igbconline.org/wp-content/uploads/2023/09/Yellowstone-
Grizzly-Bear-Investigations-2022-IGBST-Annual-Report.pdf.

27 FWS, Upper Colorado Region, Grizzly Bear in the Lower-48 States (Ursus arctos horribilis)—5-Year Status Review:
Summary and Evaluation, March 2021, https://ecos.fws.gov/docs/tess/species_nonpublish/942.pdf (hereinafter cited as
FWS, Grizzly Bear in the Lower-48 States).
28 ECOS.
29 FWS, Species Status Assessment.
30 FWS, Grizzly Bear in the Lower-48 States.
31 FWS, Species Status Assessment.
32 Ibid.
33 Ibid.
Congressional Research Service

4

link to page 6 Grizzly Bears and the Endangered Species Act

Grizzly Bear Listing Under the Endangered Species
Act
The ESA aims to conserve threatened and endangered species and their ecosystems through
mechanisms such as prohibitions on private and government conduct (ESA §9), federal agency
consultations (ESA §7), recovery plans (ESA §4(f)), and cooperation with and funding for states
(ESA §6).34 Under the ESA, FWS in the U.S. Department of the Interior and the National Marine
Fisheries Service (NMFS) in the U.S. Department of Commerce (together, the Services) are
jointly responsible for administering the law.35 FWS manages terrestrial species, such as the
grizzly bear, as well as freshwater and catadromous species.36 NMFS manages marine species and
anadromous fish.37
The ESA’s various protections and recovery mechanisms are triggered for a species when the
relevant Service lists the species as endangered or threatened. Endangered species are species that
are “in danger of extinction in all or a significant portion of [their] range.”38 Threatened species,
such as the grizzly bear, are species that are “likely to become an endangered species within the
foreseeable future throughout all or a significant portion of [their] range.”39
Species are listed as endangered or threatened following a determination that they meet the
relevant definition based on five statutory factors.40 The factors address destruction of habitat,
overutilization by humans, disease or predation, inadequate regulatory protection, and other
natural or man-made factors.41 Species may be listed (i.e., added to the list of endangered and
threatened species), reclassified (i.e., moved from the list of endangered species to threatened
species or vice versa), or delisted (i.e., removed from the list of endangered and threatened
species).42
FWS first listed the grizzly bear in the contiguous 48 states as threatened under the ESA in
1975.43 In its 1975 final rule, FWS identified several threats affecting the species.44 FWS noted
that the grizzly bear’s range had been reduced from much of the western United States to isolated
areas of Montana, Idaho, and Wyoming (see Figure 1). Within that range, FWS stated that new
roads and trails for timber harvesting and outdoor recreation had increased access to previously
inaccessible areas, leading to increased legal and illegal hunting of grizzly bears, predation of
livestock, and conflicts between grizzly bears and humans.45 FWS also observed that people were
increasingly visiting Yellowstone and Glacier National Parks and letting livestock graze in
surrounding national forests, thereby increasing detrimental pressure on the grizzly bear’s

34 See generally 16 U.S.C. §§1531-1540.
35 16 U.S.C. §1532(15).
36 50 C.F.R. §17.2(b); FWS, Endangered Species, https://www.fws.gov/endangered.
37 50 C.F.R. §17.2(b); National Oceanic and Atmospheric Administration, Endangered Species Conservation,
https://www.fisheries.noaa.gov/topic/endangered-species-conservation.
38 16 U.S.C. §1532(6).
39 16 U.S.C. §1532(20).
40 16 U.S.C. §1533(a)(1).
41 Ibid.
42 16 U.S.C. §1533(c).
43 Department of the Interior (DOI), FWS, “Endangered and Threatened Wildlife, Grizzly Bear,” 40 Federal Register
31734, July 28, 1975 (hereinafter cited as 40 Federal Register 31734).
44 Ibid.
45 Ibid.
Congressional Research Service

5

Grizzly Bears and the Endangered Species Act

remaining range.46 In addition, actual and perceived threats from grizzly bears to livestock and
humans led to regular legal and illegal killing of bears in certain states.47 FWS also pointed to
insufficient data on the grizzly bears’ population trends and habitat as impeding adequate
management and regulatory protection.48 Finally, FWS noted that the grizzly bear populations
were isolated from one another, making it difficult for other populations to reinforce their
numbers or increase their genetic diversity.49
In its 1975 listing rule, FWS also promulgated regulations governing the protection of grizzly
bears.50 For threatened species, the protections established under Section 9 of the ESA (e.g., the
prohibitions on importing, exporting, or taking the species) do not automatically apply;51 instead,
Section 4(d) of the ESA provides that these protections generally may be extended to the species
by regulations referred to as 4(d) rules or species-specific rules.52 For the grizzly bear, FWS
generally prohibited the import, commercial export, commercial transportation, sale, or take of
grizzly bears in the lower 48 states and certain activities with unlawfully taken grizzly bears.53
In its 1975 4(d) rule, FWS also allowed for certain exceptions from these prohibitions,
particularly with respect to take.54 For example, the regulations generally allowed federal and
state employees to pursue, capture, collect, and import grizzly bears and to possess, move, or
export unlawfully taken grizzly bears, so long as those activities were for scientific or educational
purposes.55 In addition, public zoos were allowed to import, commercially export, commercially
transport, and sell grizzly bears, so long as any sales were to other public zoos.56 The regulations
also allowed grizzly bears to be taken in self-defense, to defend others, or to remove nuisance
grizzly bears threatening human safety or livestock, so long as certain conditions were met.57
Finally, the regulations allowed for certain limited hunting in specified areas of northwestern
Montana.58
Although FWS has amended the grizzly bear 4(d) rule since it was promulgated, the regulations
remain largely the same as when they were enacted in 1975.59 In 1986, FWS extended the
provisions that applied to federal and state employees to tribal authorities.60 The 1986 rule also

46 Ibid.
47 Ibid.
48 Ibid.
49 Ibid.
50 Ibid.
51 16 U.S.C. §1538.
52 16 U.S.C. §§1533(d), 1539(a).
53 40 Federal Register 31734; 50 C.F.R. §17.40(b). The Endangered Species Act (ESA; 16 U.S.C. §§ 1531-1544)
defines take to mean “harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in
any such conduct.” 16 U.S.C. §1532(19).
54 50 C.F.R. §17.40(b).
55 50 C.F.R. §17.40(b)(1)(i)(D).
56 50 C.F.R. §17.40(b)(1)(iv)(B).
57 50 C.F.R. §17.40(b)(1)(i)(B)-(C).
58 40 Federal Register 31734, pp. 31734-31736.
59 See DOI, FWS, “Endangered and Threatened Wildlife and Plants; Modification of the Special Regulations for the
Grizzley Bear,” 50 Federal Register 35086, August 29, 1985; DOI, FWS, “Endangered and Threatened Wildlife and
Plants; Revision of Special Regulations for the Grizzly Bear,” 51 Federal Register 33753, September 23, 1986
(hereinafter cited as 51 Federal Register 33753); DOI, FWS, “Endangered and Threatened Wildlife and Plants; Grizzly
Bear; Removal of the Special Rule Allowing a Limited Special Hunt,” 57 Federal Register 37478, August 19, 1992
(hereinafter cited as 57 Federal Register 37478).
60 51 Federal Register 33753.
Congressional Research Service

6

Grizzly Bears and the Endangered Species Act

expanded the exception for removing nuisance bears to include grizzly bears affecting crops and
beehives.61 In 1992, a court determined that a provision of the 4(d) rule allowing a limited hunt in
northwestern Montana was invalid, and FWS amended the rule to remove that provision.62
In 1976, FWS proposed to designate critical habitat for the grizzly bear.63 In 1978, the ESA was
amended to define the existing phrase critical habitat; the amendments required the designation
of critical habitat “to the maximum extent prudent and determinable” at the time of listing based
on “the best scientific data available” after considering the economic impact, national security
impacts, and “any other relevant impact” of specifying a particular area as critical habitat.64 FWS
subsequently withdrew its grizzly bear critical habitat proposed rule in 1979.65 FWS concluded
that it must reevaluate whether it should propose critical habitat for the grizzly bear, among other
species, based on the criteria added in the 1978 amendments.66 FWS did not issue a new proposal
for grizzly bear critical habitat, and, in 1995, a federal district court upheld FWS’s decision not to
designate grizzly bear habitat.67 FWS has not subsequently proposed to designate critical habitat
for the grizzly bear.68
Grizzly Bear Recovery
Section 4(f) of the ESA provides for the creation of plans for the conservation and survival of
listed species, referred to as recovery plans.69 Recovery plans must be developed and
implemented for listed species unless the relevant Service determines that a recovery plan would
not help conserve the species.70 Section 4(f) directs the Services, to the maximum extent
practicable, to incorporate (1) site-specific management actions as necessary to achieve the plan’s
goals; (2) objective, measurable criteria that—when met—would result in a determination that the
species should be delisted; and (3) estimates of the time and cost needed to achieve intermediate
and ultimate measures to achieve the plan’s goals.71

61 Ibid. at p. 33759.
62 57 Federal Register 37478; The Fund for Animals, Inc. v. Turner, No. 91-2201, 1991 WL 206232, at *9 (D.D.C.
Sept. 27, 1991).
63 DOI, FWS, “Endangered and Threatened Wildlife and Plants Proposed Determination of Critical Habitat for the
Grizzly Bear,” 41 Federal Register 48757, November 5, 1976. The ESA defines critical habitat as (1) the areas within
the geographical area occupied by the species, at the time it is listed, which contain physical or biological features
essential to the conservation of the species and 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 that are essential for the
conservation of the species. 16 U.S.C. §1532.
64 92 Stat. 3751. The amendments also provided for certain exceptions for areas controlled by the Department of
Defense subject to an integrated natural resources management plan if FWS or the National Marine Fisheries Service
concluded the plan was beneficial for the species. See 16 U.S.C. §1533(a)(3)(B). In addition, the amendments included
provisions related to petitions to revise a critical habitat designation. 16 U.S.C. §1533(b)(3)(D). Before the 1978
amendments, Section 7 required federal agencies to ensure their actions did not result in the destruction or modification
of “habitat of such species which is determined by the Secretary, after consultation as appropriate with the affected
States, to be critical” but did not otherwise address critical habitat. See 87 Stat. 892.
65 DOI, FWS, “Requirement to Withdraw or Supplement Proposals to Determine Various U.S. Taxa of Plants and
Wildlife as Endangered or Threatened or to Determine Critical Habitat for Such Species,” 44 Federal Register 12382,
March 6, 1979.
66 Ibid.
67 Fund for Animals v. Babbitt, 903 F. Supp. 96, 115-17 (D.D.C. 1995).
68 ECOS.
69 16 U.S.C. §1533(f).
70 Ibid.
71 16 U.S.C. §1533(f)(1)(B).
Congressional Research Service

7

Grizzly Bears and the Endangered Species Act

Consistent with the requirements of ESA Section 4(f), FWS issued the Grizzly Bear Recovery
Plan in 1982 (the 1982 Recovery Plan).72 That plan reviewed grizzly bear population goals,
population and habitat limiting factors, and specific management measures to address limiting
factors in order to recover at least three populations in three distinct ecosystems and allow for the
delisting of the species.73 The plan identified six areas where grizzly bears had been observed in
the prior decade.74 Of these six areas, FWS selected the GYE, the NCDE, and the CYE to
prioritize for recovery.75
In 1983, the Department of the Interior and the Department of Agriculture created the Interagency
Grizzly Bear Committee (IGBC) by memorandum of agreement.76 The IGBC’s purpose is to
coordinate grizzly bear policy, planning, management, research, and communication between
federal, state, and tribal entities.77 The IGBC includes representatives from FWS; the U.S. Forest
Service (FS); the National Park Service (NPS); the Bureau of Land Management (BLM); the U.S.
Geological Survey; and the state wildlife agencies in Idaho, Montana, Washington, and
Wyoming.78 Tribes that manage grizzly bear habitat have representation in specific ecosystem
committees, as do local counties and other partners.79
The IGBC operates pursuant to a charter and a memorandum of understanding between the
federal and state agencies.80 The IGBC coordinates implementation of the most recent Grizzly
Bear Recovery Plan to best use resources and avoid duplicating efforts. It also supports the
development of conservation strategies by various stakeholders (e.g., states, tribes), assists with
communication to the public and between member agencies about grizzly bear management, and
aims to support FWS in delisting efforts and grizzly bear conservation post-delisting.81
In 1986, the IGBC approved interagency guidelines that outlined specific management measures
to be used in managing BLM, National Forest System, and National Park System lands in grizzly
bear ecosystems in Idaho, Montana, Washington, and Wyoming.82 These guidelines are referred to
as the Interagency Grizzly Bear Guidelines.83
FWS revised the recovery plan in 1993.84 In the 1993 Grizzly Bear Recovery Plan (1993
Recovery Plan), FWS identified five recovery zones with known populations of grizzly bears in

72 16 U.S.C. §1533(f); FWS and Don L. Brown, Montana Department of Fish, Wildlife, and Parks, Grizzly Bear
Recovery Plan, January 29, 1982, https://ia800403.us.archive.org/17/items/grizzlybearrecov1982usfi/
grizzlybearrecov1982usfi.pdf.
73 Ibid. at p. 11.
74 Ibid.
75 Ibid. at p. 12.
76 Interagency Grizzly Bear Committee (IGBC), “About Us,” https://igbconline.org/about-us/#1634593061643-
05f3cdaf-9bcb.
77 Ibid.
78 Ibid.
79 Ibid.
80 IGBC, “Interagency Grizzly Bear Committee, Charter,” 2020, https://grizzlybear.wpengine.com/wp-content/uploads/
2021/10/20190531_IGBC_CHARTER_FINAL.pdf; IGBC, “Memorandum of Understanding Amongst the Idaho
Department of Fish and Game et al.,” November 2015, https://grizzlybear.wpengine.com/wp-content/uploads/2021/10/
151104_IGBC_MOU_rev.12-13-1.pdf.
81 IGBC, “About Us,” https://igbconline.org/about-us/#1634593061643-05f3cdaf-9bcb.
82 Interagency Grizzly Bear Committee, Interagency Grizzly Bear Guidelines, 1986, pp. 3-4, http://npshistory.com/
publications/wildlife/interagency-grizzly-bear-guidelines.pdf.
83 Ibid. at p. 4.
84 Christopher Servheen, Grizzly Bear Recovery Plan, FWS, University of Montana, September 10, 1993, p. ii,
https://ecos.fws.gov/docs/recovery_plan/930910.pdf.
Congressional Research Service

8

link to page 13 link to page 20 link to page 20 Grizzly Bears and the Endangered Species Act

the lower 48 states: (1) the NCDE in Montana, (2) the CYE in Montana, (3) the SE in Idaho and
Washington, (4) the NCE in Washington, and (5) the GYE in Montana and Wyoming.85 Of these
regions, the first four were contiguous with Canadian populations of grizzly bears; the GYE
population was separate.86 FWS also identified a potential sixth region in the BE in Idaho, which
it stated contained sufficient habitat for grizzly bears but “few if any grizzly bears at this time.”87
Finally, FWS noted that another area in Colorado, the San Juan Ecosystem, was being considered
for evaluation of the potential for grizzly bear recovery but that no grizzly bears had been
confirmed in that region since 1979.88
For each of the six actual or potential grizzly bear populations FWS identified, the 1993 Recovery
Plan identified distinct recovery zones and specific recovery criteria for the population (see
Figure 2).89 The recovery plan also stated an intent to delist individual populations as they
achieved recovery.90 Any such delisting would require FWS to undertake a rulemaking process to
designate the population as a distinct population segment (DPS) and determine the DPS was no
longer an endangered or threatened species based on an analysis of the five statutory factors using
the best available scientific and commercial data.91 A DPS is a population of a species that, in
order to be designated a DPS, must be discrete from the remainder of the species and significant
to that species.92

85 Ibid.
86 Ibid.
87 Ibid.
88 Ibid.
89 Ibid. at pp. ii, 33-34.
90 Ibid.
91 16 U.S.C. §§1532, 1533(a). See section “Designation and Delisting of the Greater Yellowstone Ecosystem Distinct
Population Segment of Grizzly Bears.”
92 DOI et al., “Policy Regarding the Recognition of Distinct Vertebrate Population Segments Under the Endangered
Species Act,” 61 Federal Register 4722, p. 4725 February 7, 1996.
Congressional Research Service

9

Grizzly Bears and the Endangered Species Act

Figure 2. Grizzly Bear Recovery Zones and Estimated Distributions

Source: Interagency Grizzly Bear Committee, “Grizzly Bear Recovery Zones and Estimated Occupied Range,”
https://igbconline.org/https://igbconline.org/.
Litigation Challenging the 1993 Recovery Plan
Following the issuance of the 1993 Recovery Plan, the nonprofit organization Fund for Animals
challenged the plan, alleging that FWS had failed to include site-specific management actions and
objective, measurable delisting criteria as required by the ESA.93 In Fund for Animals v. Babbitt,
a federal district court held that FWS had adequately included site-specific management actions
in the recovery plan after assessing concerns related to hunting, road density standards, human
activities related to resource management, and unprotected linkage zones between grizzly bear
populations.94 The court concluded, however, that FWS had not adequately included objective
and measurable criteria in the recovery plan for ensuring that habitat degradation, human-caused
mortality, and genetic isolation were addressed before delisting.95 The court also concluded that
FWS had not adequately justified its selection of a population monitoring methodology that the
plan itself had acknowledged was unreliable and had limitations.96 Additionally, the court
concluded that FWS had relied on the existence of Canadian grizzly bear populations when
setting population goals without explaining how threats to the Canadian populations might affect

93 Fund for Animals v. Babbitt, 903 F. Supp. 96, 102 (D.D.C. 1995).
94 Fund for Animals, 903 F. Supp. at 106-10.
95 Fund for Animals, 903 F. Supp. at 111-13.
96 Fund for Animals, 903 F. Supp. at 113-15.
Congressional Research Service

10

Grizzly Bears and the Endangered Species Act

the analysis.97 The court directed FWS to reconsider the portions of the 1993 Recovery Plan that
it held to be inconsistent with the ESA requirements.98
Fund for Animals and FWS subsequently reached a settlement agreement.99 FWS discussed the
terms and implementation of the settlement, as well as FWS’s actions to address the court’s
opinion, in a subsequent rulemaking in 2007.100 At that time, FWS stated that the settlement
agreement required the agency to supplement the 1993 Recovery Plan to add habitat-based
recovery criteria for an ecosystem’s population before proposing to delist the population.101 FWS
issued supplements to the 1993 Recovery Plan to include habitat-based recovery criteria for the
GYE population in 2007 and for the NCDE population in 2018.102
Greater Yellowstone Ecosystem Recovery Activities
In 1993, representatives from FWS; NPS; FS; the Interagency Grizzly Bear Study Team; and state
wildlife agencies in Idaho, Montana, and Wyoming were appointed to an Interagency
Conservation Strategy Team to develop a conservation strategy for the grizzly bear in the GYE.103
In 2007, the Interagency Conservation Strategy Team released the final Conservation Strategy for
the Grizzly Bear in the Greater Yellowstone Area (2007 GYE Conservation Strategy).104 Whereas
the Interagency Grizzly Bear Guidelines were adopted to work toward recovery of the species,
the 2007 GYE Conservation Strategy was prepared to guide management of the GYE grizzly bear
population after delisting.105
FWS updated the 2007 GYE Conservation Strategy in December 2016.106 The 2016 GYE
Conservation Strategy incorporated specific, measurable habitat criteria from the 2007 Recovery
Plan Supplement.107 The 2016 Conservation Strategy identified and provided a framework for
managing two areas: the Primary Conservation Area (PCA; previously called the Yellowstone
Recovery Zone) and the demographic monitoring area. The 2016 Conservation Strategy

97 Fund for Animals, 903 F. Supp. at 115.
98 Fund for Animals, 903 F. Supp. at 118.
99 Fund for Animals v. Babbitt, 967 F. Supp. 6 (D.D.C. 1997).
100 DOI, FWS, “Endangered and Threatened Wildlife and Plants; Final Rule Designating the Greater Yellowstone Area
Population of Grizzly Bears as a Distinct Population Segment; Removing the Yellowstone Distinct Population Segment
of Grizzly Bears From the Federal List of Endangered and Threatened Wildlife; 90-Day Finding on a Petition To List
as Endangered the Yellowstone Distinct Population Segment of Grizzly Bears,” 72 Federal Register 14866, March 29,
2007, pp. 14869-14883 (hereinafter cited as 72 Federal Register 14866).
101 Ibid. at pp. 14869-14870, 14882.
102 FWS, Grizzly Bear Recovery Plan Supplement: Habitat-Based Recovery Criteria for the Yellowstone Ecosystem,
March 6, 2007, https://ecos.fws.gov/docs/recovery_plan/070313_1.pdf; FWS, Grizzly Bear Recovery Plan Supplement:
Habitat-Based Recovery Criteria for the Northern Continental Divide Ecosystem, May 15, 2018, https://ecos.fws.gov/
docs/recovery_plan/Final%20HBRC%20NCDE%20Grizzly%20USFWS%202018.pdf.
103 IGBC, “2016 Conservation Strategy for the Grizzly Bear in the Greater Yellowstone Ecosystem,” 2016,
https://myfwp.mt.gov/getRepositoryFile?objectID=93283 (hereinafter cited as IGBC, “2016 Conservation Strategy”).
The Interagency Grizzly Bear Study Team was formed in 1973 as a cooperative effort between the U.S. Geological
Survey, National Park Service, U.S. Forest Service, FWS, and the state wildlife agencies of Idaho, Montana, and
Wyoming. The team serves as a centralized entity to “collect, manage, analyze, and distribute science-based
information” about grizzly bears. Ibid., p. 98.
104 Ibid., p. 19.
105 DOI, FWS, “Endangered and Threatened Wildlife and Plants; Removing the Greater Yellowstone Ecosystem
Population of Grizzly Bears from the Federal List of Endangered and Threatened Wildlife,” 82 Federal Register 30520,
June 30, 2017, p. 30521 (hereinafter cited as 82 Federal Register 30520).
106 See IGBC, “2016 Conservation Strategy.”
107 82 Federal Register 30520, p. 30521.
Congressional Research Service

11

link to page 20 link to page 20 Grizzly Bears and the Endangered Species Act

prioritized maintaining habitat and population standards within the PCA while allowing grizzly
bears to expand beyond the PCA in “biologically suitable and socially acceptable areas.”108 The
strategy also addressed managing grizzly bear conflicts; conducting public information and
education efforts; and allowing, as appropriate, hunting of grizzly bears by regulating them as
game animals.109 FWS announced the availability of the 2016 Conservation Strategy, as well as
revised recovery criteria for the GYE population, in its 2017 final rule designating and delisting
the GYE grizzly bear population.110
Idaho, Montana, Wyoming, and the Tribes of the Wind River Reservation also each adopted
grizzly bear management plans.111 The three states entered into a memorandum of understanding
regarding how they would coordinate their management efforts.112 FS and NPS also incorporated
habitat standards and other aspects of the 2016 GYE Conservation Strategy into appropriate land
management plans.113
Northern Continental Divide Ecosystem Grizzly Bear Recovery
Activities
In 2009, the NCDE Subcommittee, a subcommittee of the IGBC, appointed the Interagency
Conservation Strategy Team for the NCDE population.114 The team released its final conservation
strategy in 2019.115 The NCDE conservation strategy noted that habitat objectives and other
provisions of the document had been incorporated (or would be incorporated prior to delisting)
into land management plans for relevant national forests, national parks, and BLM lands, as well
as management plans for the Blackfeet Indian Reservation, Flathead Indian Reservation, and
Montana state agencies.116
North Cascades Ecosystem Grizzly Bear Recovery Activities
In 1997, FWS released a supplement to its 1993 Recovery Plan with specific goals for the
recovery of the grizzly bear in the NCE.117 The supplement set out two recovery goals: (1) for the
population to be self-sustaining and large enough to offset some level of human-induced mortality

108 IGBC, “2016 Conservation Strategy”.
109 Ibid.
110 82 Federal Register 30520, p. 30512. See section “Designation and Delisting of the Greater Yellowstone Ecosystem
Distinct Population Segment of Grizzly Bears.”
111 IGBC, “2016 Conservation Strategy”, Appendixes H, I, J, N, and O.
112 Ibid. at p. 26.
113 Ibid.
114 Northern Continental Divide Ecosystem Subcommittee, Conservation Strategy for the Grizzly Bear in the Northern
Continental Divide Ecosystem, 2019, p. 8, https://myfwp.mt.gov/getRepositoryFile?objectID=93282. The Interagency
Conservation Strategy Team included representatives from FWS and the U.S. Forest Service, National Park Service,
Bureau of Land Management, U.S. Geological Survey, U.S. Department of Agriculture Wildlife Services, Montana
state wildlife agencies, Blackfeet Nation, and Confederated Salish and Kootenai Tribes.
115 Ibid.
116 Ibid. at p. 15.
117 Christopher Servheen, Grizzly Bear Recovery Plan, Supplement: North Cascades Ecosystem Recovery Plan
Chapter, FWS, University of Montana, June 23, 1997, http://npshistory.com/publications/noca/grizzly-bear/fws-
supplement.pdf.
Congressional Research Service

12

Grizzly Bears and the Endangered Species Act

and foreseeable influences of demographic and environmental variation and (2) for the population
to reach 200-400 bears and for reproducing bears to be distributed throughout the NCE.118
After decades of finding that petitions to reclassify the NCE grizzly bear population as
endangered were warranted but its listing as endangered was precluded by higher-priority listing
activities for the agency (known as a warranted but precluded finding),119 FWS concluded in June
2023 that the NCE no longer contains a grizzly bear population to list.120 In the FY2022 candidate
notice of review, FWS affirmatively concluded that the population no longer exists based on the
limited number of grizzly bear detections in the ecosystem over the last few decades and how
long it had been since the last sighting in the area (in 1996).121 The notice observed that habitat
evaluations have shown the NCE may be able to support a population of approximately 280
grizzly bears.122 Given the isolation from existing populations, however, FWS concluded that
natural recolonization of the ecosystem was unlikely.123
Following this determination, FWS proposed a rule in September 2023 to establish a nonessential
experimental population of grizzly bears in the NCE in Washington State.124 In April 2024, FWS
and NPS issued a joint Environmental Impact Statement and record of decision (ROD)
establishing a restoration plan to create a nonessential experimental population of grizzly bears in
the NCE.125 The following month, FWS issued a final rule in the Federal Register establishing a
nonessential experimental population and establishing regulations to manage the population.126
According to the ROD, FWS and NPS intend to introduce three to seven bears per year for 5-10
years until a population of 25 bears is reached. The agencies aim to reach approximately 200

118 Ibid. at p. 3.
119 16 U.S.C. §1533(b)(3)(B)(iii). See also FWS, Listing a Species as Threatened or Endangered, August 2016, p. 2,
https://www.fws.gov/sites/default/files/documents/ESA-Section-4-Listing.pdf.
120 DOI, FWS, “Endangered and Threatened Wildlife and Plants; Review of Species That Are Candidates for Listing as
Endangered or Threatened; Annual Notification of Findings on Resubmitted Petitions; Annual Description of Progress
on Listing Actions,” 88 Federal Register 41560, June 27, 2023 p. 41579 (hereinafter cited as 88 Federal Register
41560). FWS received five petitions between 1990 and 1998 to reclassify the North Cascades Ecosystem grizzly bear
population as endangered. DOI, FWS, “Endangered and Threatened Wildlife and Plants; Finding on Petition to
Reclassify the Grizzly Bear in the North Cascades Area as Endangered,” 55 Federal Register 32103, August 7, 1990;
DOI, FWS, “Endangered and Threatened Wildlife and Plants: Finding on Petition to Reclassify the Grizzly Bear in the
North Cascades Area as Endangered,” 56 Federal Register 33892, July 24, 1991; DOI, FWS, “Petitions to Change
Status of Grizzly Bear Population in Selkirk Ecosystem of Idaho and Washington et al.,”57 Federal Register 14372,
April 20, 1992; DOI, FWS, “Endangered and Threatened Wildlife and Plants; Notice of Finding on a Petition to Delist
the Grizzly Bear in the Northern Continental Divide Ecosystem, the Cabinet-Yaak Ecosystem, the Selkirk Ecosystem,
and the North Cascades Ecosystem,” 58 Federal Register 43856, August 18, 1993; DOI, FWS, “Endangered and
Threatened Wildlife and Plants: Finding on Petitions to Change the Status of Grizzly Bear Populations in the North
Cascades Area of Washington and the Cabinet-Yaak Area of Montana and Idaho from Threatened to Endangered,” 63
Federal Register 30453, June 4, 1998.
121 88 Federal Register 41560, p. 41579.
122 Ibid.
123 Ibid. at p. 41580.
124 DOI, FWS, “Endangered and Threatened Wildlife and Plants; Establishment of a Nonessential Experimental
Population of Grizzly Bear in the North Cascades Ecosystem, Washington State,” 88 Federal Register 67193,
September 29, 2023 (hereinafter cited as 88 Federal Register 67193); see also CRS In Focus IF12407, Experimental
Populations Under the Endangered Species Act, by Erin H. Ward and Benjamin M. Barczewski; CRS Report R47581,
Experimental Populations Under the Endangered Species Act and Gray Wolves, by Erin H. Ward and Benjamin M.
Barczewski.
125 National Park Service and FWS, Joint Record of Decision: Grizzly Bear Restoration Plan, April 2024,
https://parkplanning.nps.gov/showFile.cfm?sfid=729955&projectID=112008.
126 U.S. Department of Interior, FWS, Endangered and Threatened Wildlife and Plants; Establishment of a Nonessential
Experimental Population of Grizzly Bear in the North Cascades Ecosystem, Washington State, 89 Federal Register
36982, May 3, 2024 (hereinafter cited as 89 Federal Register 36982).
Congressional Research Service

13

link to page 18 Grizzly Bears and the Endangered Species Act

bears in 60-100 years.127 The geographic boundaries and the management of the nonessential
population are the same as those in the proposed rule.
The final rule sets out the geographic area for the population. The nonessential population
boundary includes all of Washington State except for the northeast corner, which currently hosts a
grizzly bear population as part of the SE Recovery Zone.128 The final rule creates three
management zones within the state that correspond to the suitability of bear habitat and the
likelihood for bear-human conflict, as shown in Figure 3. Zone A, for instance, centers on the
NCE but excludes all state and private land and will be the core habitat for reintroduction,
survival, and procreation of the experimental population.129 Zone B, while including suitable
habitat for grizzly bears in various national forests, is less likely to host a grizzly bear population
because of its distance from the NCE.130 Zone C includes the remainder of the covered area in the
state of Washington and contains large areas not thought suitable for grizzly bear populations.131

127 National Park Service and FWS, Joint Record of Decision: Grizzly Bear Restoration Plan, April 2024,
https://parkplanning.nps.gov/showFile.cfm?sfid=729955&projectID=112008.
128 89 Federal Register 36982, pp. 37002-03.
129 Ibid. at p. 37003.
130 Ibid.
131 Ibid.
Congressional Research Service

14

Grizzly Bears and the Endangered Species Act

Figure 3. Management Zones for North Cascades Ecosystem Grizzly Bear
Experimental Population

Source: U.S. Department of Interior, FWS, Endangered and Threatened Wildlife and Plants; Establishment of a
Nonessential Experimental Population of Grizzly Bear in the North Cascades Ecosystem, Washington State, 89
Federal Register 36982, p. 37003, May 3, 2024.
The final rule prohibits all take of a grizzly bear unless expressly excepted as well as the
possession, sale, delivery, transportation, shipment, import, or export of any member of the
experimental population.132 The final rule permits the intentional taking of grizzly bears to protect
human life but otherwise would prohibit intentional take.133 Incidental take would be permitted
under the proposed rule but would be subject to additional restrictions on FS land.134 Within Zone
A, federal, state, and tribal authorities could lethally remove a bear involved in a conflict if it is
not “reasonably possible to eliminate the threat through nonlethal means.”135 Within Zone B, in
addition to what is permitted in Zone A, FWS can issue a time-limited lethal take authorization to
a livestock owner if a bear depredation were confirmed, the “bear is a demonstrable and ongoing
threat, and it is not reasonably possible to eliminate the threat through nonlethal” means.136
Finally, within Zone C, in addition to what is permitted in Zone A and B, FWS or another

132 Ibid. at p. 37011.
133 Ibid. at p. 37010.
134 Ibid. Incidental take “means any taking otherwise prohibited, if such taking is incidental to, and not the purpose of,
the carrying out of an otherwise lawful activity.” 50 C.F.R. §17.3.
135 Ibid. at p. 37011.
136 Ibid.
Congressional Research Service

15

Grizzly Bears and the Endangered Species Act

authorized agency can issue a time-limited lethal take authorization to a private land owner if it is
deemed necessary for human safety or to protect property.137
Bitterroot Ecosystem Grizzly Bear Recovery Activities
In 1996, FWS issued a supplement to its 1993 Recovery Plan that evaluated potential avenues to
recover or reintroduce grizzly bears in the BE.138 The supplement found that at the time there
were no bears in the BE, the last tracks having been observed in 1946.139 The supplement
recommended that FWS explore the full range of grizzly bear recovery activities, including the
creation of an experimental population and the preparation of an accompanying environmental
impact statement (EIS) pursuant to National Environmental Policy Act (NEPA).140 In 2000, FWS
issued a final environmental impact statement (FEIS) and a ROD supporting the establishment of
a nonessential experimental population in the BE.141 The ROD created a three-phase recovery
plan: (1) creation of a Citizen Management Committee, (2) implementation of sanitation and
education efforts to prepare the land and community for the presence of grizzly bears, and (3)
placement of the bears themselves.142 FWS conditioned implementation of the last phase—
relocation of bears to the BE—on the availability of funds so as not to detract from grizzly bear
recovery efforts in other areas.143 FWS simultaneously issued a final rule formally establishing a
nonessential experimental population of grizzly bears in the BE and promulgating regulations for
the management of the experimental population.144 The final rule stated that FWS would
reintroduce at least 25 bears, mainly from Canada.145 The rule also formally created the 15-
member Citizen Management Committee that would “facilitate recovery” of the grizzly bear
population in the BE.146
In 2001, citing agency funding constraints and local opposition, FWS issued two proposed
actions (a proposed rule and a notice of intent) that, if finalized, would have abandoned the
establishment of an experimental population in the BE.147 The proposed actions would have
permitted the natural expansion of the grizzly population into the BE from surrounding

137 Ibid. FWS could issue such an authorization if a bear “present[s] a demonstrable and ongoing threat to human safety
or to lawfully present livestock ... or other property [e.g., compost, chickens, beehives] and it is not reasonably possible
to otherwise eliminate the threat by nonlethal” means. Ibid. at p. 37024.
138 Christopher Servheen, Grizzly Bear Recovery Plan Supplement: Bitterroot Recovery Ecosystem Plan Chapter, FWS,
University of Montana, September 10, 1996, p. 3, http://npshistory.com/publications/noca/grizzly-bear/fws.pdf.
139 Ibid. at p. 1.
140 Ibid. at p. 3.
141 Environmental Protection Agency, “Environmental Impact Statements; Notice of Availability,” 65 Federal Register
15903, March 24, 2000 (FWS, Final Environmental Impact Statement: Grizzly Bear Recovery in the Bitterroot
Ecosystem, March 24, 2000); DOI, FWS, “Record of Decision Concerning Grizzly Bear Recovery in the Bitterroot
Ecosystem,” 65 Federal Register 69644, November 17, 2000 (hereinafter cited as 65 Federal Register 69644).
142 65 Federal Register 69644.
143 Ibid. at p. 5.
144 DOI, FWS, “Endangered and Threatened Wildlife and Plants: Establishment of a Nonessential Experimental
Population of Grizzly Bears in the Bitterroot Area of Idaho and Montana,” 65 Federal Register 69624, November 17,
2000.
145 Ibid. at p. 69627.
146 Ibid. at p. 69628.
147 DOI, FWS, “Endangered and Threatened Wildlife and Plants; Establishment of a Nonessential Experimental
Population of Grizzly Bears in the Bitterroot Area of Idaho and Montana; Removal of Regulations,” 66 Federal
Register 33620, June 22, 2001; DOI, FWS, “Reevaluation of the Record of Decision for the Final Environmental
Impact Statement and Selection of Alternative for Grizzly Bear Recovery in the Bitterroot Ecosystem,” 66 Federal
Register 33623, June 22, 2001.
Congressional Research Service

16

Grizzly Bears and the Endangered Species Act

populations in the GYE, CYE, and NCDE.148 The proposed actions were never finalized. Despite
the final 2000 regulations establishing an experimental population, FWS did not reintroduce any
bears in the BE or establish the Citizen Management Committee.149
In 2023, a district court in Montana held that FWS’s delay in implementing the first two phases of
the ROD violated the Administrative Procedure Act (APA).150 Nonetheless, the court held that
because the FEIS was prepared more than two decades ago, FWS must prepare a new EIS before
implementing the ROD to account for any new information.151 In January 2024, FWS announced
its intent to prepare a new EIS to evaluate the potential environmental impacts of restoring grizzly
bears to the BE.152 The notice states that because “conditions have changed” FWS will evaluate a
range of recovery options, including the establishment of an experimental population.153
Designation and Delisting of the Greater
Yellowstone Ecosystem Distinct Population
Segment of Grizzly Bears
The ESA provides for the listing, protection, and recovery of “species.”154 The term species, as
defined by the ESA, may refer to a taxonomical species, a subspecies, or a distinct population
segment (DPS).155 The act does not define DPS; the Services provided their interpretation of the
term in a policy document published in 1996.156 In general, to qualify as a DPS, a population of a
species must be discrete from the remainder of the species and significant to that species.157 If the
relevant Service determines that a population qualifies as a DPS, it may evaluate the DPS based
on the factors for assessing threats to the species to determine if the DPS meets the definition of
endangered or threatened species.158 Based on that analysis, the Service may designate and list the
DPS if it qualifies as an endangered or threatened species or, if the DPS is already listed on its
own or as part of a larger listed entity, the Service may delist the DPS if it no longer qualifies.159

148 66 Federal Register 33623, p. 33624.
149 DOI, FWS, “Endangered and Threatened Wildlife and Plants; Establishment of an Experimental Population of the
Grizzly Bear in the Bitterroot Ecosystem of the States of Idaho and Montana; Environmental Impact Statement,” 89
Federal Register 3411, January 18, 2024, p. 3413 (hereinafter cited as 89 Federal Register 3411).
150 All. for the Wild Rockies v. Cooley, 661 F. Supp. 3d 1025, 1039 (D. Mont. 2023). Section 706(1) of the
Administrative Procedure Act authorizes a court to compel agency action that is “unlawfully withheld or unreasonably
delayed.” 5 U.S.C. §706(1). A court can only compel agency action, however, if that action is nondiscretionary or
ministerial. Norton v. S. Utah Wilderness All., 542 U.S. 55, 64 (2004). The court in Alliance for Wild Rockies found
that only the first two phases of the record of decision impose nondiscretionary duties on FWS. The third phase—the
reintroduction of the bears—was conditioned on availability of funds, making the reintroduction discretionary. All. for
the Wild Rockies, 661 F. Supp. 3d at 1038. The court, therefore, could not compel FWS to reintroduce bears to the
Bitterroot Ecosystem. All. for the Wild Rockies, 661 F. Supp. 3d at 1038.
151 All. for the Wild Rockies, 661 F. Supp. 3d at 1042-1043.
152 89 Federal Register 3411, p. 3413.
153 Ibid.
154 16 U.S.C. §1533.
155 16 U.S.C. §1532(16).
156 DOI et al., “Policy Regarding the Recognition of Distinct Vertebrate Population Segments Under the Endangered
Species Act,” 61 Federal Register 4722, February 7, 1996.
157 Ibid. at p. 4725.
158 See 16 U.S.C. §1533(a).
159 Ibid.
Congressional Research Service

17

Grizzly Bears and the Endangered Species Act

On two occasions, FWS has designated the GYE grizzly bear population as a DPS and delisted it
(i.e., removed it from the list of threatened and endangered species).160 In both cases, the
designation and delisting were the subject of litigation and ultimately were vacated.161 On both
occasions, courts found fault with FWS’s predictions about the effectiveness of protective
regulatory mechanisms that would persist after the species was delisted in light of the fact that
state-level management could include hunting grizzly bears and may inadequately account for
environmental changes caused by climate change.162 Further, these cases illustrate the difficulty
FWS faces in predicting the long-term health and recovery of listed species such as the grizzly
bear in a way that meets the ESA standard of using the best available scientific and commercial
data and the APA requirements for supporting agency decisions.163 These challenges in delisting
decisions generally have stemmed from the uncertainty of the regulatory landscape after delisting,
the possibility of substantial environmental change in the foreseeable future that may be difficult
to predict with certainty, and the dynamic interaction between different populations and between
the population at issue and other species that also are subject to environmental changes.
2007 GYE DPS Designation and Delisting Rule
In 2007, FWS designated the GYE grizzly bear population as a DPS and delisted it.164 At the
time, the grizzly bear was listed as threatened throughout the lower 48 states. FWS analyzed the
GYE population pursuant to its DPS policy to determine whether the population qualified as a
DPS. FWS first assessed whether the population was discrete from other grizzly bear
populations.165 FWS noted that the GYE population had been separated from other areas where
grizzly bears occur “for at least 100 years” and that the populations were separated by barriers
such as “land ownership, vegetation, and topographic patterns unsuitable for grizzly bears.”166
FWS also concluded that the population was genetically distinct from other grizzly bears.167
Having concluded the population was distinct from other grizzly bears, FWS analyzed the
population’s biological and ecological significance.168 FWS determined that the GYE population
existed in an “unusual and unique ecosystem” with food sources distinct from those of other
populations.169 In particular, FWS focused on the availability of large-bodied ungulates and other
terrestrial mammals in the greater Yellowstone area, which resulted in a higher percentage of the
population’s diet consisting of meat compared with other populations that relied primarily on
plants, such as fall berries, and insects.170 FWS also noted the GYE population’s unique reliance

160 72 Federal Register 14866; DOI, FWS, “Endangered and Threatened Wildlife and Plants; Removing the Greater
Yellowstone Ecosystem Population of Grizzly Bears from the Federal List of Endangered and Threatened Wildlife,” 82
Federal Register 30502, June 30, 2017 (hereinafter cited as 82 Federal Register 30502).
161 Greater Yellowstone Coal., Inc. v. Servheen, 665 F.3d 1015, 1032 (9th Cir. 2011); Crow Indian Tribe v. United
States, 965 F.3d 662, 681 (9th Cir. 2020).
162 Greater Yellowstone Coal., 665 F.3d at 1030-32; Crow Indian Tribe, 965 F.3d at 678-80 (9th Cir. 2020).
163 Greater Yellowstone Coal., 665 F.3d at 1030-32; Crow Indian Tribe, 965 F.3d at 678-80 (9th Cir. 2020).
164 72 Federal Register 14866.
165 Ibid. at pp. 14876-14877.
166 Ibid. at pp. 14876-14877.
167 Ibid. at p. 14877.
168 Ibid.
169 Ibid. at p. 14878.
170 Ibid.
Congressional Research Service

18

Grizzly Bears and the Endangered Species Act

on whitebark pine seeds as a major food source.171 These unique food sources made the GYE
population a significant grizzly bear population, in FWS’s view.172
In addition to positing that the GYE population was significant due to its unique ecological
setting, FWS emphasized the GYE population’s contribution to the range of the species and its
genetic characteristics.173 FWS noted that losing the GYE population—the southernmost
population of grizzly bears—would create a significant gap in the grizzly bear’s range.174 Finally,
FWS observed that the GYE population was genetically distinct from other populations, likely
due to its isolation from other populations for 100 years or more.175
Having found the GYE population to be discrete and significant, FWS determined that the
population warranted recognition as a DPS.176 After reaching this conclusion, FWS evaluated the
threats to the species using the five factors in Section 4 of the ESA. FWS concluded that the
growth, health, and expanding range and distribution of the population showed it had recovered
biologically.177 Examining the threats to the GYE population, the agency determined that the DPS
had sufficient suitable habitat and protections through federal and state management plans to
ensure the population would not be threatened with extinction in the foreseeable future.178
The Greater Yellowstone Coalition challenged the 2007 DPS designation and delisting rule under
the APA and the ESA.179 The coalition alleged that (1) the regulatory mechanisms would be
inadequate to protect the grizzly bear population once delisted, (2) FWS failed to adequately
consider the effects of global warming and factors affecting the whitebark pine, (3) the GYE
population was too small and dependent on relocating bears from other populations to maintain
genetic diversity, and (4) FWS failed to consider whether the population was recovered
throughout a significant portion of its range.180
In Greater Yellowstone Coalition v. Servheen, the district court vacated the 2007 delisting after
holding that the rule was arbitrary and capricious and inconsistent with the ESA based on the first
and second arguments described above.181 The court determined that FWS had relied on
regulatory mechanisms for protection of the GYE grizzly bear population that were unenforceable
or not sufficiently certain to occur.182 In addition, the court concluded that FWS had not
articulated a rational connection between the best available scientific and commercial data and its
conclusion that declines in the whitebark pine’s availability would not negatively impact the GYE
grizzly bear population.183 Observing that the “best available science” anticipated whitebark pines

171 Ibid.
172 Ibid.
173 Ibid.
174 Ibid.
175 Ibid. The genetic aspect of FWS’s analysis is relevant to the question of whether the GYE population is distinct and,
separately, to the question of whether it is biologically significant.
176 Ibid.
177 Ibid. at pp. 14935-14936.
178 Ibid. at pp. 14934-14935.
179 Greater Yellowstone Coal., Inc. v. Servheen, 672 F. Supp. 2d 1105, 1109 (D. Mont. 2009).
180 Greater Yellowstone Coal., Inc., 672 F. Supp. 2d at 1109.
181 Greater Yellowstone Coal., Inc., 672 F. Supp. 2d at 1118, 1120, 1126. On the other two allegations, the court
concluded that FWS had adequately explained its justification for concluding that the population had sufficient genetic
diversity and that FWS was entitled to deference for its interpretation of “significant portion of their range.” Greater
Yellowstone Coal., Inc., 672 F. Supp. 2d at 1120-26.
182 Greater Yellowstone Coal., Inc., 672 F. Supp. 2d at 1113-18.
183 Greater Yellowstone Coal., Inc., 672 F. Supp. 2d at 1118-20.
Congressional Research Service

19

Grizzly Bears and the Endangered Species Act

declining due to such factors as climate change, increasing forest fires, a mountain pine beetle
epidemic, and white pine blister rust infections, the court concluded that “much of the cited
science directly contradicts the Service’s conclusions.”184 Consistent with the court’s order, FWS
issued a notice in March 2010 that ESA protections had been reinstated for the GYE grizzly
bear.185
On appeal, the U.S. Court of Appeals for the Ninth Circuit (Ninth Circuit) affirmed the district
court’s decision to vacate the rule.186 The appeals court agreed with the district court that FWS
had not rationally supported its conclusion that potential whitebark pine declines would not
threaten the GYE grizzly bear population.187 Although the appeals court disagreed that the
regulatory mechanisms were inadequate, finding that something less than the ESA’s protections
could still be rationally deemed sufficient, the appeals court concluded that the flaws in the
whitebark pine analysis were a sufficient basis for the district court to have vacated the rule.188
2017 GYE DPS Designation and Delisting Rule
In 2017, FWS published a new final rule, once again designating the GYE population as a DPS
and delisting it.189 The agency concluded that the GYE population qualified as a DPS based on
discreteness and significance considerations similar to those it relied upon in its 2007 rule.190
FWS concluded that the whitebark pine had declined since 2002 and may no longer be a major
food source for the GYE population.191 FWS determined, however, that the population’s new
combination of food sources, which included army cutworm moths, whitebark pine, cutthroat
trout, and ungulates (e.g., bison, elk), was similarly unique from other populations to support a
finding that the population was discrete and significant.192
In its threats analysis, FWS relied primarily on the post-delisting management mechanisms
outlined in the 2016 Conservation Strategy to address potential concerns related to overutilization
and human-caused predation as well as other factors such as genetic health, changes in available
food resources, and climate change.193 In general, FWS stated that the anticipated management
response to changes in these potential threats would limit human-caused mortality through
activities such as conflict management.194 FWS also conducted a detailed analysis of the potential
effect of changes in the availability of whitebark pine on the GYE population’s diet and
anticipated mortality levels, to address the Ninth Circuit’s concerns with the 2007 rule.195
Pointing to the availability of other food resources, the grizzly bear’s dietary diversity and ability
to find other foods when one becomes less available, and stable grizzly bear population numbers
despite the whitebark pine’s decline, FWS concluded that changes in food resources did not

184 Greater Yellowstone Coal., Inc., 672 F. Supp. 2d at 1118, 1120.
185 DOI, FWS, “Endangered and Threatened Wildlife and Plants; Reinstatement of Protections for the Grizzly Bear in
the Greater Yellowstone Ecosystem in Compliance with Court Order,” 75 Federal Register 14496, March 26, 2010.
186 Greater Yellowstone Coal., Inc., 672 F. Supp. 2d at 1030-32.
187 Greater Yellowstone Coal., Inc., 672 F. Supp. 2d at 1024-30.
188 Greater Yellowstone Coal., Inc., 672 F. Supp. 2d at 1030-32.
189 82 Federal Register 30502.
190 Ibid. at pp. 30517-30519.
191 Ibid. at p. 30518.
192 Ibid. at pp. 30518-30519.
193 Ibid. at p. 30545.
194 Ibid.
195 Ibid. at pp. 30536-30540.
Congressional Research Service

20

Grizzly Bears and the Endangered Species Act

constitute a threat to the GYE grizzly bear in the foreseeable future.196 Having addressed the
Ninth Circuit’s concerns and assessed the threats to the species, FWS concluded the GYE
population was no longer a threatened species.197
The Crow Indian Tribe challenged the 2017 final rule.198 The tribe alleged that FWS had violated
the ESA and the APA by delisting the GYE DPS without considering the effect of doing so on the
remaining grizzly bears in the lower 48 states; the tribe also claimed that FWS had erred in its
five-factor analysis of threats to the DPS.199 The district court agreed.200 In Crow Indian Tribe v.
United States, the court concluded that FWS’s failure to analyze the impact of the delisting on the
grizzly bears that remained listed “entirely failed to consider an important aspect of the problem,”
rendering the rule arbitrary and capricious.201
In addition, the court determined that two flaws in the threats analysis also rendered the rule
arbitrary and capricious. First, the court concluded that to satisfy the ESA’s best available science
requirement, FWS should have required three state management plans to calibrate their
population estimators to the model that FWS had used to justify delisting.202 Citing FWS
documents that asserted that failing to include this requirement would result in a “biologically and
legally indefensible” delisting rule, the district court concluded that FWS’s decision was based
not on scientific data but on the states’ political pressure.203
Second, the court found that the two studies FWS relied upon to determine that the GYE DPS
would remain genetically self-sufficient did not support its conclusions. Those studies, in the
court’s view, concluded that the existing population size of the GYE DPS was sufficient “[f]or
short-term fitness” but that “that the long-term health of the [GYE DPS] depend[ed] on the
introduction of new genetic material.”204 The court therefore found it “illogical” for FWS to rely
on those studies to conclude that genetic health was not a threat to the population in the
foreseeable future.205 The court vacated the rule and remanded the rule to FWS to address the
three identified issues.206 FWS issued a notice in July 2019 that ESA protections had been
reinstated for the GYE population.207
FWS appealed two aspects of the district court’s remand order.208 First, it challenged the
requirement to reconsider the GYE population’s long-term genetic health.209 Second, it argued
that the ESA did not require the court to order a full Section 4(a) review of the effect of delisting
the DPS on the remnant population.210 Other stakeholders, including states and private hunting

196 Ibid. at pp. 30539-30540.
197 Ibid. at p. 30545.
198 Crow Indian Tribe v. United States, 343 F. Supp. 3d 999 (D. Mont. 2018).
199 Crow Indian Tribe, 343 F. Supp. 3d at 1003-1004.
200 Crow Indian Tribe, 343 F. Supp. 3d at 1003-1004.
201 Crow Indian Tribe, 343 F. Supp. 3d at 1004 (quoting Motor Vehicle Mfrs. Ass’n v. State Farm Mut. Auto. Ins. Co.,
463 U.S. 29, 43 (1983)).
202 Crow Indian Tribe, 343 F. Supp. 3d at 1004.
203 Crow Indian Tribe, 343 F. Supp. 3d at 1016-1017.
204 Crow Indian Tribe, 343 F. Supp. 3d at 1016-1017.
205 Crow Indian Tribe, 343 F. Supp. 3d at 1016-1017.
206 Crow Indian Tribe, 343 F. Supp. 3d at 1021.
207 FWS, “Endangered and Threatened Wildlife and Plants; Reinstatement of ESA Listing for the Grizzly Bear in the
Greater Yellowstone Ecosystem in Compliance with Court Order,” 84 Federal Register 37144, July 31, 2019.
208 Crow Indian Tribe v. United States, 965 F.3d 662, 675 (9th Cir. 2020).
209 Crow Indian Tribe, 965 F.3d at 675.
210 Crow Indian Tribe, 965 F.3d at 675.
Congressional Research Service

21

Grizzly Bears and the Endangered Species Act

and farming organizations, joined as intervenors to challenge the court’s determination that future
population estimators must be calibrated to the one used to delist the DPS.211
The Ninth Circuit generally affirmed the district court’s order. The appeals court agreed that the
underlying studies “express[ed] concerns about the long-term genetic health of the Yellowstone
grizzly” and that FWS had not ensured adequate concrete and enforceable regulatory mechanisms
to address these concerns.212 The appeals court further agreed with the district court’s
determination that FWS had failed to rely solely on the best scientific and commercial data when
it did not require calibration of future population estimators.213
The Ninth Circuit’s analysis of the remaining issue—the effect of delisting the GYE DPS on the
remnant grizzly bear population—considered in part an earlier decision of the U.S. Court of
Appeals for the D.C. Circuit (D.C. Circuit).214 In 2017, the D.C. Circuit concluded that before it
could designate and delist a DPS of gray wolves, FWS must conduct a “comprehensive review”
of the effect of the delisting on the remnant members of the species.215 Ultimately, the Ninth
Circuit distinguished the grizzly bear delisting from the gray wolf case because the remaining
grizzly bear population would remain listed. In the case of the gray wolf, FWS had created and
delisted a gray wolf DPS and then attempted to delist what remained of the gray wolf population
by concluding that the remnant population (i.e., the portion of the wolf population not included in
the DPS) did not qualify as a “species” under the act and therefore should not be listed.216
Despite finding the gray wolf case distinguishable, the appeals court held that FWS did need to
consider whether the remaining grizzly bear populations would continue to satisfy the criteria for
listing under the ESA.217 Without that analysis, the court held, FWS could not delist the GYE
DPS.218 The court noted, however, that the district court was wrong to require a full Section 4(a)
(i.e., listing) analysis of the remnant population’s eligibility for listing.219 Instead, the Ninth
Circuit held that FWS need only assess “whether there is a sufficiently distinct and protectable
remnant population, so that the delisting of the DPS will not further threaten the existence of the
remnant.”220 The Ninth Circuit directed the district court to adjust its remand order to narrow its
scope consistent with the appeals court’s opinion.221
Recent Grizzly Bear Status Assessments and Findings
In March 2021, FWS released a five-year status review for the grizzly bear in the lower 48 states
pursuant to a settlement agreement entered into with the Center for Biological Diversity in
December 2019.222 A five-year status review assesses a listed species to determine whether its

211 Crow Indian Tribe, 965 F.3d at 675.
212 Crow Indian Tribe, 965 F.3d at 679-80.
213 Crow Indian Tribe, 965 F.3d at 680-81.
214 Crow Indian Tribe, 965 F.3d at 673.
215 Humane Soc’y v. Zinke, 865 F.3d 585, 600-602 (D.C. Cir. 2017).
216 Crow Indian Tribe, 965 F.3d at 677.
217 Crow Indian Tribe, 965 F.3d at 677.
218 Crow Indian Tribe, 965 F.3d at 677-78.
219 Crow Indian Tribe, 965 F.3d at 678.
220 Crow Indian Tribe, 965 F.3d at 678.
221 Crow Indian Tribe, 965 F.3d at 681.
222 FWS, Grizzly Bear in the Lower-48 States. The Center for Biological Diversity had sued to compel FWS to conduct
a five-year status review of the grizzly bear in the lower 48 states, as required by the ESA. Stipulated Settlement
(continued...)
Congressional Research Service

22

link to page 31 Grizzly Bears and the Endangered Species Act

status has changed and whether it should be classified differently under the ESA or delisted.223
The 2021 five-year review noted several improvements in grizzly bear populations since they
were listed in 1975 and concluded that the grizzly bear in the lower 48 states was not currently in
danger of extinction throughout all of its range but could be in danger of extinction within the
foreseeable future throughout a significant portion of its range.224 This conclusion led FWS to
state that the grizzly bear in the lower 48 states met the definition of a threatened species under
the ESA and should retain its status as a threatened species.225
On February 6, 2023, FWS published preliminary findings on three petitions—one asking FWS
to delist the grizzly bear in the lower 48 states and one each asking FWS to delist the NCDE and
GYE populations.226 FWS denied the petition to delist the grizzly bear in the lower 48 states,
concluding that the petition had not presented substantial scientific or commercial data indicating
that delisting was warranted.227 FWS found, however, that the petitions for the two individual
populations had presented sufficient information to indicate that delisting may be warranted.228
Accordingly, FWS announced it was initiating a status review of the NCDE and GYE populations
to determine whether delisting is warranted.229
Considerations for Congress
The listing of grizzly bears—as a whole or in distinct populations—under the ESA remains the
subject of congressional inquiry. The 118th Congress held oversight hearings addressing the
listing of grizzly bears and introduced several bills that would direct the Secretary of the Interior
to delist grizzly bears (either the entire population in the lower 48 states or specific population
segments).230 Most of the legislative debate in the 118th Congress is on the listing status of the
GYE and NCDE populations of grizzly bears and whether these populations or the overall
population of grizzly bears in the lower 48 states should be listed under the ESA.
Some Members and stakeholders argue that grizzly bears should be delisted due to population
increases since their listing.231 These stakeholders contend that grizzly bear populations have

Agreement, Ctr. for Biological Diversity v. Bernhardt, No. 9:19-cv-00109 (D. Mont. Dec. 6, 2019). In the settlement
agreement, FWS agreed to post a status review of all grizzly bear populations by March 31, 2021. Ibid.
223 Note that all proposed changes to the status of a species listed under the act have to go through the listing process to
become final.
224 FWS, Grizzly Bear in the Lower-48 States.
225 Ibid. For more detailed information on the five-year status review and most recent species status assessment, see
report section on “Science of the Conservation and Recovery of Grizzly Bears.”
226 DOI, FWS, “Endangered and Threatened Wildlife and Plants; 90-Day Findings for Three Petitions to Delist the
Grizzly Bear in the Lower-48 States,” 88 Federal Register 7658, Feb. 6, 2023 (hereinafter cited as 88 Federal Register
7658).
227 Ibid.
228 Ibid.
229 Ibid.
230 In the 118th Congress, for example, H.R. 4997 and S. 2571 would remove grizzly bears (including experimental
populations in Idaho and Montana) from being listed under the ESA; H.R. 1419 would direct the Department of Interior
to issue a final rule to remove the Northern Continental Divide Ecosystem (NCDE) population of grizzly bears from
being listed under the ESA; H.R. 1364 would direct DOI to reissue a rule to delist the GYE population of grizzly bears
and issue a final rule to remove the NCDE population of grizzly bears from being listed under the ESA; and H.R. 1245
and S. 445 would direct DOI to reissue a rule to delist the GYE population of grizzly bears.
231 For example, see Representative Matt Rosendale, “Rep. Rosendale Releases Statement on Recovering Grizzly Bear
Population in Montana,” Press Release, February 24, 2024, https://rosendale.house.gov/news/documentsingle.aspx?
DocumentID=797.
Congressional Research Service

23

Grizzly Bears and the Endangered Species Act

increased beyond recovery plan goals, have moved out of their designated recovery areas, and are
threatening livestock and humans.232 Some individuals cite human-bear conflicts as a key concern
and argue that delisting grizzly bears would allow states greater responsibility for managing
populations, which may allow managers to better protect humans and livestock from aggressive
bears.233 Further, some stakeholders in favor of delisting grizzly bears contend that state
management of grizzly bears would be more effective than federal management.234
Members and stakeholders in favor of continuing to list grizzly bears under the ESA contend that
ESA protections will help prevent the extinction of grizzly bears and support their recovery.235 In
response to arguments to delist the entire grizzly bear population, some stakeholders assert that
the entire grizzly bear population in the lower 48 states is far from recovered and should not be
delisted.236 They note the low and extant populations of grizzly bears in the CYE and BE as
justification for keeping bears listed under the ESA.237 Some also assert that the ESA provides a
framework for conservation and recovery of species that individual states might not follow if they
retained sole responsibility for managing bears.238 Some stakeholders also suggest that states may
approve activities that are detrimental to grizzly bear populations; for example, some point to
proposed trophy hunting seasons for grizzly bears in Idaho and Wyoming as inconsistent with
conservation.239 In response to previous efforts to delist grizzly bears, some tribal stakeholders
passed legal resolutions opposing the delisting of grizzly bears, citing cultural and religious
beliefs that value grizzly bears.240
State Versus Federal Management of Grizzly Bears
Delisting the grizzly bear, or any other species listed under the ESA, generally leads to a shift in
management responsibilities from the federal government to state governments. For the first five
years after a species is delisted, the ESA requires FWS and NMFS, in cooperation with the states
in which the species is found, to monitor the species’ status.241 The federal government retains
responsibility for managing species on federal lands when they are delisted, whereas the state

232 For example, see testimony of Brian Nesvik, Director of the Wyoming Game and Fish Department, in U.S.
Congress, House Committee on Natural Resources, Water, Wildlife, and Fisheries Subcommittee, Legislative Hearing
on: H.R. 764, the “Trust the Science Act”; H.R. 886, “Save Our Seas 2.0 Amendments Act”; H.R. 1245, “Grizzly Bear
State Management Act”; and H.R. 1419, “Comprehensive Grizzly Bear Management Act,” hearings, 118th Cong., 1st
Sess., March 23, 2023, H.Hrg. 118-10 (hereinafter, hearing cited as H.Hrg. 118-10).
233 Testimony of Representative Matt Rosendale in H.Hrg. 118-10.
234 If grizzly bears were delisted from the ESA, states would be responsible for managing populations within their
boundaries.
235 For example, see Alliance for the Wild Rockies, “Alliance for the Wild Rockies Stops Cabinet-Yaak Grizzly Bear
Habitat Destruction,” press release, August 20, 2023, https://allianceforthewildrockies.org/alliance-for-the-wild-
rockies-stops-cabinet-yaak-grizzly-bear-habitat-destruction/.
236 Earthjustice, “Grizzly Bears Still Need Protections,” press release, January 18, 2024, https://earthjustice.org/experts/
perry-wheeler/grizzly-bears-still-need-protections#:~:text=
While%20their%20numbers%20have%20improved,the%20species%20is%20fully%20recovered.
237 Bonnie Rice, “Anti-Wildlife Governors Are Going After Grizzly Bears,” Sierra Club, February 10, 2023,
https://www.sierraclub.org/articles/2023/02/anti-wildlife-governors-are-going-after-grizzly-bears.
238 For example, see Center for Biological Diversity, “State Efforts to Remove Federal Grizzly Protections Move
Forward,” press release, February 3, 2023, https://biologicaldiversity.org/w/news/press-releases/state-efforts-to-
remove-federal-grizzly-protections-move-forward-2023-02-03/.
239 Testimony of Representative Jared Huffman in H.Hrg. 118-10.
240 For some examples of resolutions, see Letter from R. Bear Stands Last, Co-founder, GOAL Tribal Coalition, to
Sally Jewell, Secretary of the Interior, U.S. Department of the Interior, January 16, 2015, https://www.doi.gov/sites/
doi.gov/files/migrated/foia/os/upload/15-00269cu.pdf.
241 16 U.S.C. §1533(g).
Congressional Research Service

24

Grizzly Bears and the Endangered Species Act

manages species on nonfederal lands. For example, if grizzly bears were delisted, NPS and FS
would continue to manage grizzly bears in national parks and national forests, respectively.242
Tribal entities would continue to manage grizzly bears on tribal lands.243
Congress may consider various perspectives on state versus federal management of grizzly bear
populations when debating the status of grizzly bears under the ESA. Some stakeholders opposed
to delisting grizzly bears argue that states will not adequately manage and protect the
populations.244 They assert that existing state management plans do not reach the threshold of
having adequate regulatory protections to merit delisting and that “anti-predator hysteria” will
prevent the conservation of grizzly bears in some states.245 Specifically, some stakeholders claim
that states such as Wyoming, Idaho, and Montana may reactivate bounty and sport hunting
programs to kill grizzly bears and could weaken protections for grizzly bears that may prevent
their recovery.246 For example, under state law in Wyoming and Idaho, grizzly bears are
designated as trophy game, which is subject to hunting with a license.247 Some stakeholders assert
that trophy hunts of grizzly bears are morally objectionable and that grizzly bears should not be
killed for “sport and bragging rights.”248 Some other stakeholders note that state laws permitting
hunters to use snares, bait, hounds, and bounty payments to hunt grizzlies are detrimental to
bears.249 This sentiment is shared by numerous tribal entities that have expressed their views by
signing the Treaty of the Grizzly, which opposes trophy hunting, denounces grizzly bear habitat
alteration, and calls for consultation with tribal representatives on listing decisions related to
grizzly bears under the ESA.250 More than 170 tribal nations have signed the Treaty of the
Grizzly.

242 For example, the National Park Service states that grizzly bear management in Grand Teton and Yellowstone
National Parks would not change significantly if the GYE grizzly bear population were to be delisted. For more
information, see National Park Service, Yellowstone, Bear Management, https://www.nps.gov/yell/learn/management/
bear.htm.
243 18 U.S.C. §1862 (recognizing tribal authority to manage wildlife on tribal land), §1865 (making it a crime to hunt,
trap, fish, or remove game from tribal lands without tribal permission); New Mexico v. Mescalero Apache Tribe, 462
U.S. 324, 344 (1983) (calling tribal authority to regulate the use of its resources by tribal members and nonmembers
“unquestioned”).
244 For example, see Letter from Raul Grijalva , Ranking Member, House Committee on Natural Resources, et al. to
The Honorable Martha Williams, Director of the U.S. Fish and Wildlife Service, April 24, 2023, https://democrats-
naturalresources.house.gov/imo/media/doc/2023-04-
24%20Wolves%20and%20Grizzly%20Bears%20Letter%20to%20FWS.pdf.
245 For example, see Chris Servheen et al., “Prominent Scientists Push Back Against Delisting Grizzly Bears: Op-Ed,
When It Comes to Assessing Biological Recovery of Grizzlies, Who Is Better Informed—People Who Study Wildlife
for a Living or Governors and Legislators Who Dislike Grizzlies and Wolves?” Mountain Journal, January 13, 2022,
https://mountainjournal.org/prominent-scientists-say-removing-grizzly-bears-from-federal-protection-in-west-is-bad-
idea (hereinafter cited as Servheen et al., “Prominent Scientists Push Back”).
246 For example, see Laura Birkes, “Montana Cannot Be Trusted with Grizzly Bear and Wolf Management,”
Mongabay, May 1, 2023, https://news.mongabay.com/2023/05/montana-cannot-be-trusted-with-grizzly-bear-wolf-
management-commentary/; Laura Sheehan, “U.S. Fish and Wildlife Service Announces Status Review of Grizzly
Bears,” Defenders of Wildlife, February 3, 2023, https://defenders.org/newsroom/us-fish-and-wildlife-service-
announces-status-review-of-grizzly-bears.
247 IDAHO CODE §36-202(h) and WYO. STAT. ANN. §23-1-101(a)(xii)(A).
248 Robert Keiter, “Grizzlies, Wolves, and Law in the Greater Yellowstone Ecosystem: Wildlife Management Amidst
Jurisdictional Complexity and Tension,” Wyoming Law Review, vol. 22, no. 2 (2022),
https://scholarship.law.uwyo.edu/cgi/viewcontent.cgi?article=1465&context=wlr.
249 For example, see Servheen et al., “Prominent Scientists Push Back.” Note that the State of Montana is in the process
of considering regulations that would prohibit the intentional baiting of grizzly bears if they were delisted.
250 For more information, see Global Indigenous Council, “The Grizzly Treaty,”
https://www.globalindigenouscouncil.com/grizzly-treaty.
Congressional Research Service

25

Grizzly Bears and the Endangered Species Act

Some stakeholders who support delisting grizzly bears contend that states have adequate
measures to manage and conserve bears if they were delisted.251 For example, a Wyoming
Wildlife Taskforce report recommends that the governor take steps to bring the GYE population
of grizzly bears under state management in Wyoming.252 According to the governor’s office,
Wyoming has a state management plan for grizzly bears in place and will amend it by changing
annual management targets and mortality thresholds to ensure the plan meets ESA standards and
the population remains above federal thresholds.253 Some stakeholders also assert that states are
better equipped to manage populations than the federal government and have greater
understanding of local conditions to tailor population-specific management plans.254 Some states
with grizzly bears are taking steps to develop management strategies and build coordination. The
states of Montana, Wyoming, and Idaho prepared a memorandum of agreement (Tri-State MOA)
to coordinate their management of the GYE grizzly bear population if it were delisted.255 The Tri-
State MOA addresses discretionary mortality and conservation of grizzly bears in the GYE
population. It also contains management objectives and monitoring and adaptive management
provisions, and it aims to correspond to FWS recovery criteria if the species were delisted. This
agreement aims to complement state management plans created by Idaho, Montana, and
Wyoming.256
Some state laws provide conditions for hunting grizzly bears that aim to limit hunting if it is
detrimental to grizzly populations. For example, Montana state law directs a Commission on
Grizzly Bears to “establish hunting season quotas for grizzly bears that will prevent the
population of grizzly bears from decreasing below sustainable levels.”257
Livestock Protection and Human-Bear Conflicts
Some grizzly bears have been known to attack and harass livestock and threaten and kill humans
under certain circumstances.258 As grizzly bear populations increase and expand into developed
areas, human-bear conflicts (which include livestock depredation) are expected to increase,
according to stakeholders.259 The ESA provides a defense against civil and criminal penalties for
individuals who take listed species—including grizzly bears—if individuals adequately

251 For example, see Gordon, Petition.
252 The task force comprises members selected by the Governor of Wyoming. The task force has a position paper
supporting state management of grizzly bears and a final report with similar sentiments. See Wyoming Wildlife
Taskforce at https://sites.google.com/wyo.gov/wyomingwildlifetaskforce/home.
253 Wyoming Game and Fish Department, “Wyoming Seeks State Management of Grizzly Bears,” press release,
September 16, 2021, https://wgfd.wyo.gov/News/Wyoming-Seeks-State-Management-of-Grizzly-Bears.
254 Testimony of Representative Harriet Hageman in H.Hrg. 118-10.
255 Wyoming Game and Fish Commission et al., Tri-State Memorandum of Agreement Regarding the Management,
Genetic Health, and Allocation of Discretionary Mortality of Grizzly Bears in the Greater Yellowstone Ecosystem
Among Wyoming Game and Fish Commission, Wyoming Game and Fish Department, Montana Fish and Wildlife
Commission, Montana Fish, Wildlife and Parks, Idaho Fish and Game Commission, and Idaho Department of Fish and
Game, 2024, https://fwp.mt.gov/binaries/content/assets/fwp/commission/2024/jun/wildlife/moa-actual_tri-state-grizzly-
bear_jan-2024-wgfc_ifgc.pdf (hereinafter cited as Wyoming Game and Fish Commission et al., Tri-State Memorandum
of Agreement).
256 Ibid.
257 Mont. Code Ann. §87-5-302 (2023).
258 For example, see National Park Service, “Visitor Injured in Incident with Bear,” press release, May 19, 2024,
https://www.nps.gov/grte/learn/news/visitor-injured-in-incident-with-bear.htm.
259 Smith L. Wells et al., “Grizzly Bear Depredation on Grazing Allotments in the Yellowstone Ecosystem,” Journal of
Wildlife Management, vol. 83, no. 3 (December 2018), https://wildlife.onlinelibrary.wiley.com/doi/10.1002/
jwmg.21618.
Congressional Research Service

26

Grizzly Bears and the Endangered Species Act

demonstrate that the taking was in self-defense or to protect a family member or other
individual.260 This defense is not available, however, for taking endangered species that threaten
or kill livestock. Under a special 4(d) rule for grizzly bears, grizzly bears can be removed if they
are threatening livestock and can be killed, under certain conditions, if they are committing
significant depredation of livestock.261 Lethally taking a grizzly bear that is preying on livestock
is allowed if (1) it is not possible to relieve the threat through live capture and release; (2) the
taking is done in a humane manner and authorized by federal, state, and tribal authorities; and (3)
the taking is reported within five days.262
Some stakeholders who favor delisting grizzly bears contend that livestock losses due to grizzly
bears are significant and create a sense of fear among ranchers for the safety of their family and
livestock.263 They argue that lifting federal protections and returning management to states would
better address human safety and grizzly bear depredation of livestock.264 They support this
position by asserting that state managers have a better understanding of local ranching practices
and grizzly bear behavior and that state managers can balance the needs of ranchers and bears
better than federal managers.265 These stakeholders also note that states have several existing laws
that address the conservation of grizzly bears.266
Some stakeholders who are against delisting grizzly bears argue that state laws and regulations
that authorize the take of grizzly bears that harm livestock or threaten humans would not
adequately protect grizzly bear populations if they were delisted.267 These stakeholders claim that
under state laws, grizzly bears would be taken at levels that would reduce their population size.268
For example, under Montana state law, state policy is to manage grizzly bears to minimize
conflicts with humans and livestock and to “use proactive management to manage grizzly bear
distribution and prevent conflicts, including non-lethal and preventative measures, as well as,
trapping and lethal measures.”269 This policy, in part, has prompted some stakeholders to assert
that Montana law would allow for nearly unregulated killing of grizzly bears that threaten
livestock (with no definition of what is considered threatening).270 Montana law also allows a

260 16 U.S.C. §1540(b)(3).
261 40 Federal Register 31734, pp. 31734-31736; 50 C.F.R. §17.40(b).
262 50 C.F.R. §17.40(b)(i)(C). The U.S. Department of Agriculture, Animal and Plant Health Inspection Service,
collaborates with FWS and state wildlife agencies to assist livestock owners that experience livestock depredation due
to grizzly bears and other species. Federal wildlife specialists use nonlethal methods and, when necessary, lethal
removal to prevent grizzly bears from attacking cattle and sheep under this program. For more information, see Joe
Szuszwalak, FWS, “USFWS and USD Providing Additional Support to Montana Livestock Producers,” press release,
June 3, 2020, https://www.fws.gov/press-release/2020-06/collaboration-support-livestock-producers-after-increased-
grizzly-bear.
263 Testimony of Karli Johnson in H.Hrg. 118-10.
264 U.S. Representative Matt Rosendale, “Rosendale Legislation to Delist Montana Grizzly Bear Population Receives
Committee Hearing,” press release, March 23, 2023, https://rosendale.house.gov/news/documentsingle.aspx?
DocumentID=543.
265 For example, in reference to the GYE grizzly bear population, see Gordon, Petition.
266 Wyoming Game and Fish Commission et al., Tri-State Memorandum of Agreement. (A summary is found in the Tri-
State MOA.)
267 For example, see Servheen et al., “Prominent Scientists Push Back.”
268 Testimony of Christopher Servheen in H.Hrg. 118-10.
269 MONT. CODE ANN. §87-5-301, as amended by 2023 Mont. S.B. 295.
270 Center for Biological Diversity, “State Efforts to Remove Federal Grizzly Protections Move Forward,” press
release, February 3, 2023, https://biologicaldiversity.org/w/news/press-releases/state-efforts-to-remove-federal-grizzly-
protections-move-forward-2023-02-03/.
Congressional Research Service

27

Grizzly Bears and the Endangered Species Act

person to kill a grizzly bear without a permit if the bear is attacking or killing livestock.271
Because the ESA preempts state law, management of the grizzly bear is governed by federal, not
state, law. Some actions permitted by Montana law, such as trapping, would currently violate the
ESA, but if grizzly bears were delisted from the ESA and were threatening livestock, an owner
could complain to the state and have the bear removed or taken.272 If delisted, grizzlies could be
taken under the Montana state law only if an annual quota for taking grizzly bears had not been
surpassed.273
Ranchers can receive compensation from the federal government and some states for livestock
lost to grizzly bears. For example, some states and the federal Livestock Indemnity Program
provide compensation to ranchers who lose livestock to bear attacks under certain
circumstances.274 FWS also coordinates with state agencies to address human-grizzly conflicts.
FWS has a Grizzly Bear Recovery Program with several conflict specialists to assist states, tribes,
and local communities in relocating grizzly bears; implement grizzly bear conflict management
and mitigation; and conduct outreach and education activities.275
FWS efforts to alleviate conflicts with grizzly bears have been contentious. In 2019, some
stakeholders sued FWS, as well as FS, for authorizing the lethal take of up to 72 grizzly bears in
the GYE over a 10-year period in anticipation of conflicts with ranchers with federal grazing
permits.276 FWS authorized the take in the context of FS’s proposal to authorize livestock grazing
for 10 years on the Upper Green River Area Rangeland in Wyoming.277 Although the district court
upheld the agencies’ actions, the U.S. Court of Appeals for the Tenth Circuit (Tenth Circuit)
reversed in part.278 In relevant part, the Tenth Circuit concluded that FWS’s biological opinion
violated the ESA by failing to consider limiting lethal take on female bears in light of the existing
“mortality sink” (i.e., mortality exceeding or nearly exceeding survival) for female grizzly bears
in the area affected by the grazing permits.279 The court remanded the biological opinion and FS’s
decision to issue the grazing permits to the agencies without vacating either action.280
Science of the Conservation and Recovery of Grizzly Bears
In the debate over whether to delist grizzly bears, Congress may consider perspectives and
scientific findings on the status and viability of grizzly bear populations. Some stakeholders assert
that the entire grizzly bear population should be delisted because population recovery goals have
been met and, in some cases, surpassed.281 Some other stakeholders favor delisting certain distinct

271 MONT. CODE ANN. §87-5-301, as amended by 2023 Mont. S.B. 295.
272 Ibid.
273 Ibid.
274 For more information on the Livestock Indemnity Program, see U.S. Department of Agriculture, “Livestock
Indemnity Program (LIP),” https://www.fsa.usda.gov/programs-and-services/disaster-assistance-program/livestock-
indemnity/index.
275 For more information, see FWS, “Grizzly Bear Recovery Program,” https://www.fws.gov/office/grizzly-bear-
recovery-program.
276 Ctr. for Biological Diversity v. Haaland, 603 F. Supp. 2d 1094, 1098-99 (D. Wyo. 2022).
277 Ibid. at p. 1103.
278 W. Watersheds Project v. Haaland, 69 F.4th 689 (10th Cir. 2023).
279 W. Watersheds Project, 69 F.4th at 698.
280 W. Watersheds Project, 69 F.4th at 698.
281 U.S. Senator for Idaho James E. Risch, “Risch, Crapo Reintroduce Bill to Delist Greater Yellowstone Grizzly,”
press release, February 16, 2023, https://www.risch.senate.gov/public/index.cfm/2023/2/risch-crapo-reintroduce-bill-to-
delist-greater-yellowstone-grizzly.
Congressional Research Service

28

link to page 25 Grizzly Bears and the Endangered Species Act

populations of grizzly bears;282 they assert that the GYE and NCDE populations have surpassed
recovery goals for population size and should be delisted as DPSs.283 This perspective is
illustrated in petitions to FWS to designate a DPS for the GYE and the NCDE, which are under
review.284
Other stakeholders state that grizzly bears should remain listed based, in part, on recent status
reports from FWS that recommend a threatened listing and on potential long-term threats to
grizzly bear populations, such as climate change and development.285 Some conservationists also
argue that certain populations of grizzly bears are essentially extirpated and should recover (e.g.,
through the possible introduction of an experimental population) before the species is delisted.286
In addition, some stakeholders question the accuracy of population counts for grizzly bears that
are reported to surpass recovery benchmarks. They argue that counting grizzly bears is
challenging and results vary significantly, thus implying that population counts might not be
accurate.287
Congress may consider several scientific findings when evaluating the varying perspectives on
the status of grizzly bear populations. In 2021, FWS issued a five-year status review evaluating
grizzly bears from 2011 to 2021. FWS also conducted a species status assessment (SSA) for
grizzly bears in 2022.288
The 2021 five-year review evaluated the status of the grizzly bear population and its population
viability according to three conservation biology principles: redundancy, resiliency, and
representation.289 FWS concluded that the entire grizzly bear population in the lower 48 states
should remain a threatened species under the ESA.290 This finding was based on several factors
that threaten grizzly bears and activities implemented to conserve grizzly bears. For example, the
five-year review evaluated the current resiliency of separate populations of grizzly bears to
evaluate the condition of the entire population. The assessment concluded that the GYE and
NCDE populations have high resiliency to natural and human-caused perturbations; it also stated
that the SE population has moderate resiliency and the CYE population has low resiliency. The
BE and NCE populations are functionally extirpated, according to the review, and therefore have

282 See “Recent Grizzly Bear Status Assessments and Findings.”
283 Gordon, Petition.
284 88 Federal Register 7658.
285 For example, see Perry Wheeler, “Grizzly Bears Still Need Protections,” Earthjustice, January 18, 2024,
https://earthjustice.org/experts/perry-wheeler/grizzly-bears-still-need-protections.
286 Clark Corbin, “Idaho Sen. Jim Risch Introduces Bill to Fully Delist Grizzly Bears in Lower 48,” Idaho Capitol Sun,
August 14, 2023, https://idahocapitalsun.com/2023/08/14/idaho-sen-jim-risch-introduces-bill-to-fully-delist-grizzly-
bears-in-lower-48/.
287 David Mattson, “More Confusion About Yellowstone National Park’s Grizzly Bear Population,” The Daily
Montanan, May 29, 2023, https://dailymontanan.com/2023/05/29/more-confusion-about-yellowstone-national-parks-
grizzly-bear-population/.
288 FWS, Grizzly Bear in the Lower-48 States, and FWS, Species Status Assessment, supra note 15. There was no
review in 2016.
289 According to FWS, redundancy is “the ability for the species to withstand catastrophic events, for which adaptation
is unlikely, and is associated with the number and distribution of populations”; resiliency “is the ability for populations
to persist in the face of stochastic events, or for populations to recover from years with low reproduction or reduced
survival, and is associated with population size, growth rate, and the quality and quantity of habitats”; and
representation “is the ability of a species to adapt to changes in the environment and is associated with its diversity,
whether ecological, genetic, behavioral, or morphological.” FWS, Species Status Assessment Framework: An
Integrated Analytical Framework for Conservation, version 3.4, August 2016, https://www.fws.gov/sites/default/files/
documents/species-status-assesment-framework-2016-08-10.pdf.
290 FWS, Grizzly Bear in the Lower-48 States. According to FWS, this conclusion was based on an analysis of the best
scientific information available and was an assessment of the viability of the population.
Congressional Research Service

29

Grizzly Bears and the Endangered Species Act

no resiliency.291 The report concluded that the high resiliency of some individual populations does
not make the overall population currently in danger of extinction. However, within the
foreseeable future, the report noted that the overall population would be less likely to “withstand
plausible stochastic events, catastrophic events, or retain sufficient adaptive capacity to withstand
environmental change 30 to 45 years into the future,” among other things, and should be listed as
threatened.292
The 2022 SSA evaluated grizzly populations with data up to December 2020 and reported similar
results.293 The 2022 SSA, however, did not make listing recommendations for the entire grizzly
bear population or individual populations. The 2022 SSA also evaluated the grizzly bear
population with respect to its recovery criteria. For grizzly bears, certain criteria are measured for
the recovery of each population:
• Minimum population size measured by unduplicated females and cubs
• Distribution of reproductive females across a recovery zone and not concentrated
in one area
• Annual human-caused mortality limits that would allow the population to achieve
and sustain recovery
• Habitat-based recovery criteria294
The 2022 SSA reported that the GYE and the NCDE grizzly bear populations met all of the
recovery criteria. The other four populations did not meet all of the recovery criteria, according to
the report.295
Some stakeholders raise the question of how grizzly bear populations are adapting to changes in
their environment and if they have the ability to adapt to long-term environmental changes in the
future.296 Some studies provide results that may, in part, answer this question.297 For example, one
study reported that certain grizzly bear populations are adapting to changes in their ecosystem.298
The study reported that body fat levels in grizzly bears in the GYE did not significantly change
over 20 years even though competition for food and resources increased (e.g., grizzly bear density
increased in the region).299 This study also notes that even though grizzly bear populations are
resilient to short-term environmental and ecosystem changes, they might be affected by long-term
changes such as climate change, drought, and changes in forage species such as whitebark pine.300

291 Ibid.
292 Ibid.
293 Species status assessments are done annually for grizzly bears, and the information from these assessments is used
for the five-year status reviews.
294 FWS, Species Status Assessment.
295 Ibid.
296 U.S. Geological Survey, “New Publication Synthesizes Climate Effects on Bears and their Interactions with
Humans,” press release, April 11, 2024, https://www.usgs.gov/programs/climate-adaptation-science-centers/news/new-
publication-synthesizes-climate-effects-bears.
297 Andrea Corradini et al., “Evidence for Density-Dependent Effects on Body Composition of a Large Omnivore in a
Changing Greater Yellowstone Ecosystem,” Journal of Global Change Biology, vol. 29, no. 16 (June 1, 2023), pp.
4496-4510, https://doi.org/10.1111/gcb.16759.
298 Ibid.
299 Ibid.
300 Ibid.
Congressional Research Service

30

Grizzly Bears and the Endangered Species Act

Members of Congress and stakeholders have also taken positions on the proposed rule to establish
a nonessential experimental population of grizzly bears in the NCE in Washington state.301 The
intent of the experimental population is to “support reintroduction and recovery of grizzly bears
within the NCE and provide the prohibitions and exceptions under the Act necessary and
appropriate to conserve the species.”302 Some stakeholders argue that introducing grizzly bears in
the NCE will increase human-wildlife conflicts, livestock depredation, and property damage.303 In
the 118th Congress, H.R. 5927 would withdraw the proposed rule to create the experimental
population of grizzly bears in the NCE and would withdraw a draft EIS addressing the
experimental population.
Legislation to Delist the Grizzly Bear from the ESA
Congress is considering bills in the 118th Congress that would direct the Secretary of the Interior
to delist the grizzly bear without going through the delisting process under the ESA. For example,
H.R. 1419, H.R. 1245, and S. 445 would direct the Secretary of the Interior to issue a final rule to
delist the NCDE grizzly bear population and reissue a final rule to delist the GYE population.304
H.R. 4997 and S. 2571 would direct the Secretary of the Interior to remove grizzly bears and
associated experimental populations from the threatened and endangered lists under the ESA.
H.R. 1364 would direct the Secretary of the Interior to remove grizzly bears in the GYE and
NCDE from the list of threatened and endangered species. All of the bills would preclude judicial
review of the listing rules. In considering these and other measures addressing grizzly bears,
Congress may evaluate arguments for and against using legislation to make listing decisions
under the ESA and precluding judicial review of these actions.
Some stakeholders supporting these bills argue that grizzly bear populations have recovered and
contend that the ESA makes it difficult to delist species.305 Members of Congress have introduced
legislation over time to delist grizzly bears, though none of the bills have been enacted.306 Some
stakeholders opposed to these bills argue that if Congress passed a law delisting grizzly bear
populations, it would bypass the process for delisting under the ESA that takes into account the
best available science and scientific analysis.307 They also argue that it would set a precedent for

301 88 Federal Register 67193.
302 Ibid.
303 For example, see Representative Dan Newhouse, “Challenging the Biden Administration’s Ill-Conceived Grizzly
Bear Relocation Proposal,” press release, March 28, 2024, https://newhouse.house.gov/media/weekly-columns-and-op-
eds/challenging-biden-administrations-ill-conceived-grizzly-bear.
304 82 Federal Register 30502 (for the GYE grizzly population).
305 For example, see U.S. Representative Matt Rosendale, “Rosendale Legislation to Delist Montana Grizzly Bear
Population Receives Committee Hearing,” press release, March 23, 2023; Senator James E. Risch, “Risch Leads
Bicameral Legislation to Fully Delist Grizzly Bears in Lower 48 States,” press release, July 27, 2023,
https://www.risch.senate.gov/public/index.cfm/pressreleases?ID=27A8E7BC-0198-4360-8175-6DBEF0B940E2.
306 For example, in the 118th Congress, the House of Representatives and the Senate passed joint resolutions to overturn
ESA listings for the lesser prairie chicken and the northern long-eared bat (S.J.Res. 9 and S.J.Res. 24, respectively).
The President vetoed both resolutions on September 26, 2023, and stated that S.J.Res. 9 and S.J.Res. 24 “would
overturn a science-based rulemaking that follows the requirements of the law, and thereby undermines the ESA.” White
House, “Message to the Senate on the President’s Veto of S.J.Res. 9,” press release, September 26, 2023,
https://www.whitehouse.gov/briefing-room/statements-releases/2023/09/26/message-to-the-senate-on-the-presidents-
veto-of-s-j-res-9/; White House, “Message to the Senate on the President’s Veto of S.J.Res. 24,” press release,
September 26, 2023, https://www.whitehouse.gov/briefing-room/statements-releases/2023/09/26/message-to-the-
senate-on-the-presidents-veto-of-s-j-res-24/.
307 Testimony of Stephen Guertin, Deputy Director for FWS, in H.Hrg. 118-10.
Congressional Research Service

31

Grizzly Bears and the Endangered Species Act

addressing other listed species through legislation rather than the listing process under the
ESA.308

Author Information

Erin H. Ward
Benjamin M. Barczewski
Coordinator of Research Planning/ALD
Legislative Attorney

Pervaze A. Sheikh

Specialist 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.

308 U.S. Congress, House Committee on Natural Resources, Full Committee Markup, 118th Cong., April 27, 2023;
White House, “Message to the Senate on the President’s Veto of S.J.Res. 9,” press release, September 26, 2023,
https://www.whitehouse.gov/briefing-room/statements-releases/2023/09/26/message-to-the-senate-on-the-presidents-
veto-of-s-j-res-9/; White House, “Message to the Senate on the President’s Veto of S.J.Res. 24,” press release,
September 26, 2023, https://www.whitehouse.gov/briefing-room/statements-releases/2023/09/26/message-to-the-
senate-on-the-presidents-veto-of-s-j-res-24/.
Congressional Research Service
R48116 · VERSION 2 · NEW
32

Download PDF

Download EPUB

Revision History

Jun. 28, 2024

HTML · PDF

Metadata

Topic areas

Energy Policy

Environmental Policy

Report Type: CRS Report

Source: CRSReports.Congress.gov

Raw Metadata: JSON