The agency concluded that “We do not expect that fragmentation within the GYE grizzly bear DPS boundaries will constitute a threat to the GYE grizzly bear DPS now or in the foreseeable future” (USFWS, 2017, p. 30524).

The USFWS recognized habitat fragmentation and that this influence threatens grizzly bear populations (Parmenter et al., 2003). The impacts of fragmentation elsewhere are well known (Fahrig, 2003, Fischer and Lindenmayer, 2007). Habitat loss and fragmentation are among the top causes of species decline (Haddad et al., 2015). In the above USFWS quote, however, the agency did not consider rural housing trends. The construction of rural homes has been the primary form of land-use change in the GYE (Rasker and Hansen, 2000). Montana’s Gallatin County was once the fastest-growing county in the state, and lost 95,680 acres due to sprawl from 1990 to 2016 (Headwaters Economics, 2024). Moreover, single-family homes rose from comprising 11,640 acres in 1990 to 28,938 acres in 2016, with one-third of the lots exceeding 10 acres (Rasker, 2018). Gallatin County is located inside the DPS. If we consider an additional ten Montana counties that are fully or partially inside the DPS, a mean of 31,472 acres was converted into sprawl from 1990 to 2016 (mostly single-family homes) (Headwater Economics, 2024). Based on present trends and using the 20-county GYE delineation, Hansen and Phillips (2018) predicted that the number of homes will increase to 503,465 by 2050. When located in grizzly bear-occupied areas, such construction represents a diminishment of grizzly bear habitat. Road and highway density are also a negative influence on bear habitat, and sometimes serve as an indicator of forest fragmentation (Heilman et al., 2002). For a detailed account of past efforts to thwart GYE sprawl, see Wilkinson (2025). Housing encroaching on protected areas is a national problem (Volker et al., 2010; Hjerpe et al., 2020). The threat of sprawl is not confined to US parks. A similar situation occurs in the Canadian portion of the NCDE (Horejsi, 1989). Therefore, housing development in the GYE is a major component of ongoing habitat fragmentation.

The agency declared, “We do not consider human population growth on private land to constitute a threat to the GYE grizzly bear DPS now or in the foreseeable future” (USFWS, 2017, p. 30526).

However, human population growth is probably the leading cause of biodiversity loss (Hansson and Göttmark, 2022). Its growth is typically accompanied by habitat fragmentation and persecution (McKee et al., 2004). The above agency statement becomes questionable based on other GYE data. During 1970–1999, the GYE experienced a 58% increase in population size and a 350% increase in rural land development (Gude et al., 2006). Many investigators reported the unprecedented influx of new residents (Rasker and Hansen, 2000; Johnson et al., 2003; Gude et al., 2006). The arrival of new people seeking an improved lifestyle continues, and the city of Bozeman is a prime example. Current GYE population growth and housing density are predicted to double by 2050. This growth trend projects a human population of 846,146 by 2050 (Hansen and Phillips, 2018). Therefore, human population growth on certain private land is a threat to the grizzly bear.

The agency said, “We will continue efforts to reestablish natural connectivity between the GYE and other grizzly bear populations” (USFWS, 2007, p. 14896).

However, the USFWS has failed to have a consistent connectivity policy position (Gunther et al., 2014). In 1993, the agency assigned importance to grizzly bear “linkage zones” and indicated that providing connectivity between recovery zones was a long-term objective (USFWS, 1993, p. 24). In 2004, the Interagency Grizzly Bear Committee remarked in a memo that the long-term future of the GYE grizzly bear population was bleak unless critical corridor connections were secured (Thompson, 2004, p. 708). In 2011, the USFWS made another supportive statement regarding the need for corridors (U.S. Fish and Wildlife Service (USFWS), 2011). Moreover, in the 2017 Final Regulation, the agency stated that natural connectivity is important and bears will benefit from occasional gene flow (USFWS, 2017, p. 30518). The USFWS observed that “commenters and peer-reviewers thought connectivity was essential for long-term viability” (USFWS, 2017, p. 30579).

Nevertheless, in response to public comments, the USFWS remarked that “Lack of connectivity is not a threat to the existence of the GYE DPS [bears]” and “… is not required to maintain the GYE DPS [bears]” (USFWS, 2017, p. 30581). As a result, one commenter observed that the agency thought connectivity was “both vital and unnecessary” (USFWS, 2017, p. 30579). In a follow-up to the 2017 regulations, the USFWS did not change its position, indicating that “Connectivity is not necessary for the current genetic health of the GYE grizzly bear population…” (USFWS, 2018, p.18740).

Many scientists have stressed the need for habitat connectivity between US grizzly bear populations in the technical literature (Craighead and Vyse, 1996; Servheen et al., 2002; Carroll et al., 2004; Proctor et al., 2004) and federal regulations testimony (e.g. Craighead et al., 2005). State and federal organizations have also elaborated on the benefits of corridors for grizzly bears (Montana Fish Wildlife and Parks, 2013; Yellowstone Ecosystem Subcommittee, 2016). Non-government organizations (NGOs) have undertaken activities to preserve habitat connectivity in certain locations between the GYE, NCDE, and BE (Shafer, 2015). Creating connectivity on US public lands does raise legal issues (Keiter, 2018).

There is evidence that corridors facilitate animal movement (Beier and Noss, 2008; Gilbert-Norton et al., 2010, 2013) and other benefits (Chetkiewicz et al., 2006), including allowing dispersal, migration, foraging, and range shifts. Gene flow is another key reason (Shafer, 2022). International guidelines have been developed to facilitate corridor creation (Hilty et al., 2020). Conservation case studies document their implementation around the world. For an example of a dual-country large-scale effort to facilitate habitat connectivity, see Hebblewhite et al. (2022). Connectiyity conservation is now addressed by the top science journals (Brodie et al., 2025). Therefore, the USFWS’s position on habitat connectivity in the GYE has changed over the decades from for, to unconcerned, to again for today.

The agency’s legal position on listing and habitat connectivity also raises concerns. They remarked that the absence of linkage zones would not stop the delisting if other recovery goals were met (USFWS, 2007), and their position in 2017 remained unchanged (USFWS, 2017, pp. 30580–30581). This decision was likely made because they argued that usable corridors were not the intention of the ESA, and therefore, they did not insist on them in the 2007 and 2017 regulations (USFWS, 2017). However, two scientific societies (American Society of Mammalogists and Society for Conservation Biology) objected to this viewpoint on May 10, 2016, in their comments on the 2016 Proposed Regulations (USFWS, 2016). They argued that “the ESA obligate[s] the USFWS to manage the metapopulation of grizzlies in the lower 48 states, not just each population individually” (SCB/ASM, 2016). Corridors or habitat connectivity can facilitate gene flow, but if that ideal is not possible, there is a management alternative.

The USFWS also said that translocating grizzly bears into the GYE would only occur as a “last resort” (USFWS, 2017, p. 30536).

Translocation is a “management technique often used in mitigation for endangered species protection whereby an individual, population, or species is removed from its habitat to be established in another area of similar or identical habitat” (Groom et al., 2006, p. 709). The agency later changed its mind about this management technique being a last resort, likely due to critiques of its genetics policy (e.g. Shafer, 2022) and its support by GYE grizzly bears scientists (Turnock et al., 2025). During 2024, the State of Montana released several grizzly bears from the NCDE into the GYE to facilitate gene flow. However, translocation should not occur without some careful outcome considerations (Mildigans et al., 2018; Evans et al., 2023). This option is receiving more attention due to climate change (Butt et al., 2020). This management technique was tried decades ago for the CYE (Servheen et al., 1995) and has continued at other lower 48 state locations (Turnock et al., 2025). Therefore, the agency’s position on translocation as expressed in its regulations has changed from being “a last resort” in 2017 to being actively implemented in 2024.

The USFWS stated that “Grizzly bears in these peripheral areas are not biologically necessary for the GYE grizzly bear population” (USFWS, 2017, p. 30510).

Dismissing other nearby grizzly bear populations as irrelevant to delisting was part of the reason why a 2018 federal court judge ruled to relist the bear (Crow Indian Tribe et al. v. USA (2017) 17-cv-00089). In the court’s words, the agency “failed to consider how reduced protection in the GYE would impact the other grizzly bear populations” (2018 US Dist. LEXIS 163319, 48 ELR 20168, 2018 WL 4568418 (D. Mont. September 24, 20180)). This judge would not have agreed with the following agency statement: “The management and potential status of other grizzly bear populations is outside the scope of this review” (USFWS, 2017, p. 30552). The USFWS recorded what one commenter said, “Recovery must address the entire lower 48 states as a whole unit, instead of splitting out the GYE” (USFWS, 2017, p. 30558). Today, the USFWS is looking at other grizzly bear populations as potentially contributing to the persistence of the GYE population.

The USFWS remarked, “We do not consider human population growth on private lands to constitute a threat to the GYE grizzly bear DSP now or in the foreseeable future” (USFWS, 2017, p. 30526).

This highly questionable remark may have contributed to a false sense of security. It contrasts with the statements and findings of other scientists and practitioners. Gunther (2015) calculated that 41% of all GYE grizzly bear conflicts occurred on private land. Similarly, Schwartz et al. (2010) found that 62% of grizzly bear mortalities occurred on private land outside the GYE Primary Conservation Area (PCA). According to Hansen (2011), private land in the GYE is a mortality sink for grizzly bears, and even low-density residential settlements are sinks (Schwartz et al., 2012). Mark Bruscino, a State of Wyoming grizzly bear biologist and member of the Interagency Grizzly Bear Study Team (IGBST), indicated that the largest long-lasting threat to grizzly bears is human development on private land (Quammen, 2016), which will only worsen over time. Glick and Freese (2004) perceived that the future of biodiversity in GYE is determined by what happens to its private property. Knight et al. (1999) thought private land development was the greatest threat to the grizzly bear. The topic was deemed sufficiently important to stimulate the writing of a law journal article (Middleton et al., 2022).

The agency also explained, “On private lands, we have no authority to limit developed sites and do not think it is necessary” (USFWS, 2017, p. 30575).

They do have the tools to take some action. For example, they can acquire easements or impose the ESA. They can acquire land or enter into cooperative agreements. Under the fastest growth (boom) scenario, Gude et al. (2007) predicted that 180,000 homes would be built in the GYE by 2020. However, based on 2016 data, the number of homes built was approximately 227,000 (Gude et al., 2017). Based on Schwartz et al.’s (2012) model predictions, heavy private land development will occur outside the GYE PCA and within the current distribution of grizzly bears. Kolankiewiczl et al. (2024) said sprawl is the greatest threat to the GYE.

Private land constitutes 31% of the GYE (Hansen & Phillips 2018), but only 750,000 acres (11%) are protected by conservation easements (Keiter, 2020, p. 148). According to Sells and Costello (2023), approximately 50% of existing grizzly-bear-occupied areas are privately owned. Thus, the importance of private land in corridors between the GYE and the NCDE should not be underestimated (Gigliotta et al., 2022).

Offer (2020) identified landowners in Peck et al.’s (2017) three computer-modeled habitat corridors, stretching northwest–southeast from the GYE to the NCDE. The author found that the central corridor (using Peck’s least-cost-pathway model with an equal resistance surface) had 41.7% of its total length intersected by private land.

Over four decades ago, Varley (1988) famously stated that “No one, it seems, wants to tackle the issue of threats to the park (or ecosystem) that arise on private lands (p. 222).” Although this situation is changing based on problem awareness, coordinated efforts to address this problem are lacking (Wilkinson, 2022). Today, the USFWS is very aware of the importance of private land to grizzly bear recovery.

The USFWS emphatically stated, “There is no evidence that changes in food resources will become substantial impediments to the long-term persistence of the GYE grizzly bear population” (USFWS, 2017, p. 30544).

Climate change entails a shift in temperature and weather caused by natural or anthropogenic influences. The typical effects include rising temperatures, sea-level rise, more frequent and stronger weather events, changes in rainfall, and impacts on biological diversity. Whitebark pine seeds are an important part of the grizzly bear’s diet. However, a warming climate will allow mountain pine beetles (Dendrotonus ponderosae) to spread and kill white pine trees. This predicament is ongoing.

However, an IBGST-organized workshop looked at this situation differently in 2010. Except for being forced into closer proximity to humans, this workshop concluded that the GYE grizzly bear would unlikely be affected by climate change (Servheen and Cross, 2010). It is therefore unsurprising that in 2017, the USFWS said, “Most grizzly bear biologists in the United States and Canada do not expect habitat changes predicted under climate change scenarios to directly threaten grizzly bears” (USFWS, 2017, p. 30521). However, based on the advice received from other scientists, a federal judge disagreed (Gardner, 2013). For an elaboration of why this judge may have thought climate change was a threat, see Mattson (2019). While controversial, other scientists regard the negative impact of climate change on whitebark pine as a problem for the grizzly bear (Buotte et al., 2016; Raffa et al., 2012). It is therefore unclear whether grizzly bears will survive without the whitebark pine tree, but this lack of information does not imply that there will be no potential negative future influence on the bear if the trees diminish or disappear. Today, members of the IGBST agree that climate change may negatively influence the persistence of the tree in the GYE (Costello et al., 2015). One thing seems clear. Climate change will force more human-grizzly contact, which will likely have negative outcomes for the bear.

The USFWS also said, “We do not consider management removals a threat to the GYE grizzly bear population now, or in the foreseeable future” (USFWS, 2017, p. 30529).

Management removal usually means killing a bear due to some severe transgression like injuring or killing a visitor, repeatedly feeding on livestock, or being a recurrent problem at campgrounds. However, they can also be moved elsewhere or given to zoos. In the GYE population from 2002 to 2019, management removal accounted for 64% of all mortalities (USFWS, 2021). The USFWS and US Forest Service were sued in 2019 for allowing the lethal removal of 72 grizzly bears over ten years because of anticipated problems with sheep ranching [Center for Biological Diversity versus Haaland, 603. Supp. 2d 1094, 1098 (D. Wyo, 2022)]. Thus, management removals at this level will not enhance the future persistence of this GYE grizzly bear population.

The agency also concluded that “this source of mortality [hunting] does not constitute a threat to the GYE grizzly bear DPS now, or in the foreseeable future” (USFWS, 2017, p. 30530).

In response to the 2016 draft grizzly bear delisting rule, one regulations commentator remarked, “We [USFWS] did not adequately consider how hunting could impact the grizzly bear population” (USFWS, 2017, p. 30588). This is true. For example, a study of grizzly bear hunting in British Columbia from 1980-2016 revealed that excessive hunter harvest was the norm (Artelle et al., 2013). The downsides of hunting are poorly understood (Mattson, 2020).

The agency explained another result of hunting for other species. “From 2002 to 2014, 31 percent (97) of human-caused grizzly bear mortalities in the GYE were in self-defense or defense of other persons [usually elk hunter] kills…” (USFWS, 2017, p. 30528). Therefore, many grizzly bear kills are a result of elk (Cervus canadensis) hunters defending an elk carcass or spring black bear (Ursus americanus) hunters killing a grizzly bear by mistake. In addition, many non-hunter grizzly bear killings go unreported (McLellan et al., 2018).

The agency also stated that “Hunting should never threaten the GYE grizzly bear population” (USFWS, 2017, p. 30588). For an abundant carnivore like the American black bear, assuming wise management strategies are in place, the populations should not be threatened by hunting (Hristienko and McDonald, 2007). However, the situation with the far less abundant US grizzly bear warrants more caution. Looking at brown bear data spanning 30 years, researchers observed that hunting disrupted the interactions between age-specific survival and environmental factors, altered reproduction strategies, and life expectancy (Bischof et al., 2018). Therefore, kills resulting from the deliberate hunting of grizzly bears may not be inconsequential sources of mortalities. However, the unintentional lethal encounters while hunting elk or spring black bears add to this mortality count. The 1975 listing of the grizzly bear as a threatened species and the first grizzly bear management plan (USFWS, 1983) mentioned legal hunting as a probable cause of decline.

The USFWS remarked, “The DMA [Demographic Monitoring Area] provides more than enough suitable habitat for a large, robust, healthy, and viable population and will continue to do so in the foreseeable future” (USFWS, 2017, p. 30551).

First, as some commenters pointed out, it is not clear what “foreseeable future” means. However, the current population is not large enough for long-term evolutionary adaptation (i.e., hundreds of years or centuries). For both short and longer periods, the GYE grizzly bear population will continue to slowly lose genetic diversity unless natural immigration from other populations or translocation occurs (Shafer, 2022).

The agency also said, “There is no published method to deductively calculate minimum habitat values required for a healthy and recovered population” (USFWS, 2017, p. 30509).

Minimum habitat area, or minimum area requirement, is defined as “the amount of space (suitable habitat) that is required for long-term persistence of a population” (Pe’er et al., 2014, p. 93). Although this agency statement may be true, many scientists have proposed minimum habitat areas based on various criteria (Allendorf and Ryman, 2002; Bader and Sieracki, 2022). These estimates should not be dismissed because they cannot be accepted as precise. One approach to derive the minimum habitat area is population viability analysis (PVA) (Chaudhary and Oli, 2019). “Population viability analysis (PVA) …entails evaluation of data and models for a population to anticipate the likelihood that a population will persist for some arbitrarily chosen time in the future” (Boyce, 1992, p. 481).

The agency stated, “First, it is important to understand that the proportion of mortalities outside the DMA is steadily increasing over time and that any population inference should be based on mortalities inside the DMA” (USFWS, 2017, p. 30568).”

The agency’s long-standing policy of not counting bears outside the DMA raises a significant issue. This practice prevents a good approximation of the total GYE grizzly bear population size because the population of grizzly bears in the GYE’s “occupied range” extends beyond those in the DMA.

The USFWS said, “The State [Montana] will manage discretionary mortality to retain the opportunity for natural movements of bears between ecosystems” (USFWS, 2017, p. 30581).

In other words, the state believes it can manage grizzly bear hunting in the region between the GYE and NCDE while simultaneously facilitating inter-ecosystem dispersal. Why did this policy arise? To finalize the Memorandum of Agreement (MOA) between the states of Montana, Idaho, and Wyoming, the state of Montana insisted that any statement suggesting that grizzly bear migration was needed to retard the genetic erosion of the GYE population be deleted (USFWS, 2017, p. 30610). The USFWS agreed to accommodate the State’s suggested language in the Final Rule, which ultimately stated that “genetic connectivity is not required for delisting, and the genetic health of the GYE DPS is very strong.”

The agency recognized that grizzly bears moving outside the DMA will find themselves on land where bears are unwelcome by all three states (USFWS, 2017, p. 30580). The agency also knew that states of Idaho and Montana “will actively prevent the successful recolonization of an unoccupied historical range because of the potential for conflict” (USFWS, 2017, p. 30580). The MOA and 2017 Federal Register Final Rule inform us that grizzly bear population growth will be reduced based on “allowable” mortality, due to hunting, accidental deaths, and management removals. This may result in migrating bears being considered “uncountable deaths,” rather than grouped into total allowable mortality. The states of Montana and Wyoming identified these areas as “no-death count zones.”

The USFWS indicated they wish to “facilitate occasional gene flow from nearby grizzly bear populations like in the NCDE” (USFWS, 2017, p. 30536). However, at the same time, the states want to drop the grizzly bear population size on the fringes of their range, the very locations where migrating bears may be found. This conflict in dispersal and mortality goals was pointed out in the media (Koshmrl, 2024). The agency admitted that “Delisting of the GYE grizzly bear population may reduce the potential for NCDE grizzly bears to disperse to the GYE due to increased mortality inside the GYE DPS” (USFWS, 2018). Dispersing grizzly bears in Canada suffered increased levels of mortality (Proctor et al., 2002). Agencies exacerbate this problematic dispersal issue when hunting migrating bears in corridors is allowed. The agency recorded “Peer reviewers and public commenters suggested that hunting be prohibited in connectivity areas and key wildlife corridors” (USFWS, 2017, p. 30589). There are no grizzly bear mortality limits for areas outside the GYE DMA (USFWS, 2018).

Therefore, sport hunting in corridors will exacerbate the stated USFWS goal of continuing interagency efforts to provide and maintain movement opportunities for grizzly bears. The former US grizzly bear recovery coordinator (Servheen et al., 2024) and others also dispute the scenario that grizzly bears should be hunted in migration corridors. Hunting and facilitating bear migration, when allowed together, is problematic when seeking to augment a bear genome through inter-ecosystem movement. Therefore, the USFWS past position on hunting grizzly bears in GYE habitat corridors was dictated by adjacent states, which was likely precipitated by politics.

The USFWS remarked, “We cannot reliably predict on any human timescale that the status of the bear will deteriorate at all, much less that it will become in danger of extinction in the future” (USFWS, 2017, p. 30607).

As the southernmost range of the grizzly bear in North America, the GYE population is threatened by many factors, including continued habitat loss and fragmentation, hunting and poaching, management removal, climate change, accidents, and other stresses (Hansen, 2006; Schwartz, 2010; Keiter, 2018). Therefore, the above agency statement, even on a decades-long time scale, dismisses ongoing major negative influences as inconsequential. Today, the agency would likely not embrace such a rosy prediction.

Many issues in the 2017 Final Regulations were given inadequate attention or were compromised by misinformation. Some were overlooked even by regulation commenters and judges. Some USFWS thinking has changed since 2017. Nevertheless, since such activity to delist the grizzly bear in the lower 48 states may continue, this review should provide insight into how the USFWS might respond if asked to write another GYE grizzly bear delisting rule. If that happens, one can anticipate that some writing may be influenced by the federal administration’s political ideology.