This data set represents the 2018 elk seasonal range boundaries for Wyoming. Seasonal range delineations depict lands that are important in each season for certain biological processes within a herd unit. Seasonal range boundaries are based on long-term observation data, specific research projects, and professional judgement. Ranges were originally digitized at a scale of 1:100,000 using USGS 1:100,000 DRGs as a backdrop for heads up digitizing, and are revised as needed by the Wyoming Game and Fish Department. Current seasonal range definitions are based on a 1990 document drafted by the Wyoming Chapter of The Wildlife Society in cooperation with the Wyoming Game and Fish Department and federal land agencies.

Elk (Cervus elpahus canadensis) within the northern section of the Bighorn Mountains display altitudinal migration. In the spring, they migrate from the eastern foothills up into the mountains, and in the fall, they head back down to lower elevations (fig. 67). The herd, which numbers around 5,500, primarily winters along the eastern foothills of the northern Bighorn Mountains just west of Sheridan, though some will winter north towards Bighorn Canyon. Winter ranges are a mix of shrubs and herbaceous grasslands, largely supported by private land. During migration animals travel an average one-way distance of 21 mi (34 km) ranging from as little as 5 mi (8 km) to as far as 83 mi (134 km). In spring, animals migrate off winter range and head west up the eastern side of the Bighorn Mountains. They traverse up the slopes generally following clearings between extensive pine forests. Summer ranges consist of evergreen forests that are predominantly lodgepole pine with smaller areas of open herbaceous grasslands. The summer range is almost entirely within the Bighorn National Forest. The population size of the herd has remained relatively steady over the last decade. While there is a higher concern for the animals on their winter range because it largely consists of private land, their migration routes are much safer because they are relatively short, do not cross any highways and are for the most part within the National Forest. These data provide the location of migration routes for elk in the North Bighorn population in Wyoming. They were developed from 109 migration sequences collected from a sample size of 63 animals comprising GPS locations collected every 2 hours.

Migratory movements of elk within the Piney herd unit, a large area encompassing the eastern side of the Wyoming, include short (i.e., 10 miles) to medium (i.e., 30 miles) distance migrations. These elk migrate from low elevation elk feedgrounds and native winter ranges in the Upper Green River Basin to high elevation summer ranges in the Wyoming Range. In summer, some elk head further west into the Grey’s River Basin from the Bench Corral and Forest Park feedgrounds. Challenges for Piney elk include energy development, especially in the southern portion of the herd unit. These data provide the location of migration routes for Elk (Cervus canadensis) in the Piney herd in Wyoming. They were developed from Brownian bridge movement models using 306 migration sequences collected from a sample size of 158 animals comprising GPS locations collected every 2-8 hours.

The Fossil Butte (hereafter referred to as the Monument in this section of the report) elk population winters in the southern Wyoming Range between Fossil Butte National Monument and Cokeville (fig. 45). During spring, they migrate north short (11 mi [18 km]) to medium (74 mi [119 km]) distances. The segment of the elk population that winters near the Monument migrates into the Wyoming Range at the head of the Hams Fork and LaBarge Creek. This population departs their summer ranges during the beginning of archery season in early fall for the Monument, where no hunting is allowed. Elk wintering closer to Cokeville migrate north in the spring along the western edge of the Wyoming Range. Cokeville collared elk departed their summer ranges later in the season, timed with weather events and vegetation senescence. Challenges to this elk herd include crossing U.S. Highway 89. These data provide the location of migration routes for Elk (Cervus canadensis) in the Fossil Butte herd in Wyomi ...

The Owl Creek elk herd, with 7,500–8,500 wintering elk, inhabits the northwest corner of the Wind River Reservation, traversing habitats along the Absaroka Range and the Owl Creek Mountains (fig. 36). The herd contains resident and migratory elk; migrants travel an average 10.7 mi (17.2 km) one way. Elevations range from 6,000 ft (1,829 m) at Wind River near Crowheart to 12,200 ft (3,700 m) in the Absaroka Range, and summits in the Owl Creek Mountains reach 8,000–9,800 ft (2,438–2,987 m). Habitats range from sage and desert scrub in the lowlands surrounding the Wind River Range to upland meadows, aspen groves, Pinus contorta (lodgepole pine) forests, and alpine tundra. When on the Wind River Reservation, the elk are under the sovereignty of the Eastern Shoshone Tribe and Northern Arapaho Tribe of the Wind River Reservation, Wyoming. During spring migration, some of the elk cross the East Fork Wind River to FS lands. Other migrations are entirely in the reservation, including the upper tributaries near Washakie Needles, or the Owl Creek Mountains. Residents in the herd also use the Owl Creek Mountains, particularly the portion east of Blondy Pass. Many areas contain significant evidence of past hunting and ceremonial activity, and according to Shoshone ethnography, elk were significant game acquisition in the prereservation era of the 1800s (Shimkin, 1947). This elk herd remains culturally and economically valuable to Tribal members who sustainably harvest elk under a game code established in 1984 (Nickerson, 2019; Public Law 86-634m 86th Congress, H.R. 4386). Habitats are virtually free of human disturbance and development aside from Tribal member livestock grazing and a few Tribal-owned and operated oilfields in the desert winter range. Threats to habitat include drought and climate change or biological invasions of nonnative cheat grass and feral horses contributing to poor range conditions. In 2022, Tribes started working in partnership with the Wind River Agency of Bureau of Indian Affairs, U.S. Fish and Wildlife Service, Wyoming Game and Fish Department, Wyoming Legislature, Wyoming Livestock Board, and the Wild Sheep Foundation to reduce the feral horse population and design projects to restore habitats to greater productivity (Kikonow, 2023). These mapping layers show the location of the Migration routes for Elk (Cervus canadensis) in the Owl Creek population in Wind River Reservation. They were developed from 77 migration sequences collected from a sample size of 16 animals comprising GPS locations collected every 1 hour.

The Baggs pronghorn herd inhabits south-central Wyoming, to the southwest of Rawlins, Wyoming, bounded by Interstate 80 to the north and the Wyoming–Colorado border to the south (fig. 32). This herd unit includes the Atlantic Rim and the eastern part of the Red Desert Basin, which is an arid to semiarid Wyoming big sagebrush-steppe habitat marked by severe winters. Although the landscape is generally remote, human development, including oil and natural gas infrastructure and cattle and sheep ranching, affects the habitat the herd uses. Therefore, a GPS-collaring study (2013–16) was initiated to evaluate the effects of human-caused and environmental change on pronghorn in the Red Desert Basin (Reinking and others, 2018, 2019). Pronghorn in this herd are semimigratory to nomadic and migrate around the Sierra Madre. In general, pronghorn winter to the west of the Sierra Madre range and near Wyoming Highway 789, and spring migrations expand to the southeast, the east, or the north. However, migration routes are not always consistent, and pronghorn can backtrack across their migration route or remain on winter range year round. Some individuals in this herd seasonally overlap with the Elk Mountain herd (refer to the “Elk Mountain Pronghorn” section in this report). Property boundary or legacy livestock ranching fences remain prevalent in the area, restrict pronghorn movement, and pose a direct mortality risk. Interstate 80, the biggest barrier that Baggs pronghorn encounter, is rarely crossed by pronghorn because the interstate has a high traffic volume, net-wired right-of-way fencing, and part of the Union Pacific Railroad parallels the interstate. Wyoming Highway 789, which runs to the north and to the south and divides this herd, is another barrier. However, pronghorn can cross Wyoming Highway 789 more easily than Interstate 80 (Robb and others, 2022). Beginning in 2009, a series of underpasses were constructed on Wyoming Highway 789, to the north of Baggs, Wyoming, but they are used mostly by mule deer. Baggs pronghorn also share habitat and compete for resources with feral horses in the Adobe Town HMA and potentially the Salt Wells Creek HMA, to the west of Wyoming Highway 789 in the southern Red Desert Basin (Hennig, 2021; Hennig and others, 2021, 2022, 2024). Furthermore, feral horses, pronghorn, and cattle have a high degree of overlap at water sources in the Red Desert Basin (Hennig and others, 2021). These mapping layers show the location of the migration routes for pronghorn (Antilocapra americana) in the Baggs population in Wyoming. They were developed from 90 migration sequences collected from a sample size of 32 animals comprising GPS locations collected every ~2 hours.