West Slope Winds

West Slope Winds encompasses 143,252 acres of subalpine terrain on the Bridger-Teton National Forest, rising from Irish Canyon at 8,400 feet to the Sweetwater Needles at 10,321 feet, with Sioux Pass marking a major saddle at 9,450 feet. The landscape drains through multiple watersheds: the North Fork Silver Creek headwaters originate here, while Big Sandy River, Sagebrush Creek, East Sweetwater River, Dutch Joe Creek, and Lander Creek all carry water from these slopes. This network of streams and seeps creates the hydrological backbone of the area, sustaining distinct plant communities across elevation and moisture gradients.

The forest composition shifts with elevation and aspect. At lower elevations and on drier slopes, Rocky Mountain Lodgepole Pine Forest and Rocky Mountain Subalpine Dry-Mesic Spruce-Fir Forest dominate, with lodgepole pine (Pinus contorta) and Engelmann spruce (Picea engelmannii) forming the canopy. On north-facing slopes and in wetter settings, Rocky Mountain Subalpine Mesic-Wet Spruce-Fir Forest develops, where subalpine fir (Abies lasiocarpa) becomes increasingly prominent. At the highest elevations, Rocky Mountain Subalpine-Upper Montane Limber-Bristlecone Pine Woodland takes hold, with limber pine (Pinus flexilis) and the threatened whitebark pine (Pinus albicaulis) persisting on exposed ridges. Grouse whortleberry (Vaccinium scoparium) carpets the understory in coniferous stands. Quaking aspen (Populus tremuloides) forms scattered groves in transition zones. On south-facing slopes and ridgetops, Inter-Mountain Basins Mountain Big Sagebrush Steppe replaces forest, with mountain big sagebrush (Artemisia tridentata) dominating. Wet meadows and fens at higher elevations support the threatened western prairie fringed orchid (Platanthera praeclara), along with elephant's-head lousewort (Pedicularis groenlandica), Ross' avens (Geum rossii), and sky pilot (Polemonium viscosum). Beaver Rim phlox (Phlox pungens), vulnerable (IUCN), occurs on specialized substrates.

Large carnivores structure the food webs across this landscape. The Canada lynx hunts snowshoe hares through dense spruce-fir stands, while the threatened grizzly bear (Ursus arctos horribilis) forages for roots, berries, and ungulates across meadows and forest edges. The threatened North American wolverine (Gulo gulo luscus) ranges across high ridges and talus slopes. Gray wolves (Canis lupus) prey on moose (Alces alces) and pronghorn (Antilocapra americana) in open sagebrush and aspen zones. Clark's nutcrackers (Nucifraga columbiana) harvest whitebark pine seeds, dispersing them across the subalpine landscape. American pikas (Ochotona princeps) inhabit talus fields and rocky outcrops, their high-pitched calls marking their territories. The greater sage-grouse (Centrocercus urophasianus), near threatened (IUCN), depends on sagebrush steppe for breeding and foraging. Streams support populations of Colorado River cutthroat trout (Oncorhynchus virginalis pleuriticus) and golden trout (Oncorhynchus aguabonita), critically imperiled (IUCN), which occupy cold headwater reaches.

A visitor ascending from Irish Canyon experiences a steady transition in forest structure and composition. The initial lodgepole stands give way to denser spruce-fir forest as elevation increases and moisture becomes more reliable. The understory darkens, and the sound of water becomes constant—first as the distant rush of a named creek, then as the immediate presence of seepage and springs feeding the wet meadows. Breaking above treeline near the Sweetwater Needles, the forest opens suddenly into sagebrush steppe and alpine meadow, where the wind becomes audible and the view extends across the high country. The shift from the enclosed, humid cove forest to the exposed ridgeline is marked by a change in light, temperature, and the species underfoot: from the soft carpet of grouse whortleberry to the sparse, low-growing alpine herbs. Descending through Sioux Pass, the forest composition shifts again, reflecting the aspect and moisture regime of the eastern slope, creating a landscape where elevation, water, and exposure continuously reshape what grows and what lives here.

The Wind River Mountains and surrounding region have been inhabited and used by Indigenous peoples for millennia. The Eastern Shoshone have occupied the Wind River Mountains and western Wyoming for at least 3,500 years, with archaeological evidence suggesting a presence extending back 12,000 years. A specialized group known as the Tukudika or Sheepeaters historically lived at high elevations in the Wind River and Absaroka Mountains, developing expertise in hunting bighorn sheep and surviving in alpine environments. The broader region was also seasonally used by the Shoshone-Bannock, Nez Perce, Crow, Cheyenne, Ute, Blackfeet, and Lakota for hunting elk, bighorn sheep, and bison, gathering plants including bitterroot and biscuitroot, extracting obsidian for tool-making, and conducting spiritual ceremonies and vision quests. The 1863 Treaty of Fort Bridger recognized Shoshone territory as including lands west of the Wind River Mountains, where this area is located. The 1868 Treaty of Fort Bridger subsequently established the Wind River Reservation on the eastern side of the range, where the Northern Arapaho and Eastern Shoshone tribes now reside together. The region contains archaeological evidence of this long occupation, including high altitude villages and Dinwoody-style petroglyphs unique to the Wind River and Bighorn basins.

Early American exploration of the region began in the early nineteenth century when fur trappers and mountain men traversed these mountains. John Colter is believed to have been the first to cross the area around 1807–1808, potentially crossing the Continental Divide near this region. The Lander Cut-Off of the Oregon Trail, surveyed in 1857 by Frederick W. Lander, passed just south of the present-day forest, carrying over 13,000 emigrants in its first year as the first federally funded road project west of the Mississippi.

By the late nineteenth century, advancing timber harvest and overgrazing threatened the landscape. In response, President Benjamin Harrison established the Yellowstone Park Timber Land Reserve on March 30, 1891, via presidential proclamation—the first forest reserve created under the Forest Reserve Act of 1891. President Theodore Roosevelt expanded this reserve on May 22, 1902, through Proclamation 473, adding 5 million acres and dividing the Yellowstone Forest Reserve into four divisions: the Teton, Wind River, Absaroka, and Shoshone divisions. The administrative structure of the forest underwent several reorganizations. The Bridger National Forest was established on July 1, 1911, as a separate entity from part of the Bonneville National Forest, but was absorbed into the Wyoming National Forest in 1923. On March 10, 1941, President Franklin D. Roosevelt signed Executive Order 8709, renaming the Wyoming National Forest to the Bridger National Forest in honor of mountain man Jim Bridger. The Bridger-Teton National Forest was officially established as a single administrative unit in 1973 through the merger of the Bridger and Teton National Forests.

Federal protection of specific lands within the forest expanded significantly in the latter twentieth century. The Bridger Wilderness, originally established as a primitive area in 1931, was formally designated under the Wilderness Act of 1964. This designation was expanded in 1984 through the Wyoming Wilderness Act, which also created the Gros Ventre Wilderness. The area was evaluated during the Roadless Area Review and Evaluation II (RARE II) process conducted in 1978 and 1983 to identify lands for potential wilderness designation. West Slope Winds is designated as a 143,252-acre Inventoried Roadless Area, protected under the 2001 Roadless Area Conservation Rule and managed within the Pinedale Ranger District of Bridger-Teton National Forest.

Vital Resources Protected

Headwater Protection for Four Federally Listed Fish Species

The North Fork Silver Creek headwaters, Big Sandy River, and East Sweetwater River originating in West Slope Winds feed the Upper Green River and New Fork River systems, which ultimately supply critical habitat for four federally endangered fish: bonytail, Colorado pikeminnow, pallid sturgeon, and razorback sucker. These species depend on cold, sediment-free spawning substrates and unobstructed migration corridors that begin in these high-elevation streams. Road construction in headwater zones would introduce chronic sedimentation from cut slopes and culvert barriers, directly degrading the spawning habitat these species require for survival and recovery.

Climate Refugia and Elevational Connectivity for Threatened Alpine Species

The area's subalpine and alpine ecosystems—spanning from 8,400 feet at Irish Canyon to 10,321 feet at Sweetwater Needles—provide climate refugia for species sensitive to warming, including Canada lynx (which has designated critical habitat here), whitebark pine (federally threatened), and black rosy-finch (IUCN endangered). The unfragmented elevational gradient allows species to shift upslope as temperatures rise, a migration pathway that becomes impassable once roads fragment the landscape. Roadless conditions preserve the continuous forest and meadow connectivity that these species require to track suitable climate conditions across the landscape.

Migration Corridor for Ungulate Populations Under Severe Stress

West Slope Winds contains critical segments of the Wyoming Range mule deer and Sublette antelope migration corridors. Recent winter mortality exceeded 50% in the Wyoming Range mule deer herd, making access to this area's summer range essential for population recovery. The roadless condition maintains landscape permeability—the ability of animals to move unimpeded across the terrain—which is disrupted by roads that fragment habitat, increase vehicle strikes, and create barriers to seasonal movement. Loss of this corridor would compress already-stressed populations into smaller ranges with reduced forage and increased disease transmission risk.

Grizzly Bear Recovery Habitat and Carnivore Connectivity

The area supports forage and security habitat for grizzly bears (federally threatened), whose populations have improved dramatically since 1990 but remain dependent on large, undisturbed territories. Canada lynx, wolverine (federally threatened), and gray wolf also utilize high-elevation habitats here. Roads fragment these territories, increase human-wildlife conflict through vehicle strikes and poaching access, and create edge effects that reduce the security cover these carnivores require. The roadless condition preserves the spatial continuity necessary for these species to maintain viable populations across the Greater Yellowstone Ecosystem.

Threats from Road Construction

Sedimentation and Temperature Increase in Cold-Water Fisheries

Road construction requires cut slopes and fill material that erode into adjacent streams, introducing fine sediment that smothers the clean gravel spawning beds that bonytail, Colorado pikeminnow, pallid sturgeon, and razorback sucker require for reproduction. Simultaneously, removal of riparian forest canopy along road corridors allows direct solar heating of streams, raising water temperatures above the cold-water thresholds these species tolerate. The headwater streams in West Slope Winds are already functioning at the thermal and sediment limits suitable for these federally endangered fish; road-induced degradation would eliminate critical spawning habitat with no possibility of recovery without complete road removal.

Habitat Fragmentation and Loss of Elevational Migration Pathways

Road networks divide the continuous forest and meadow mosaic into isolated patches, preventing Canada lynx, whitebark pine, and black rosy-finch from shifting upslope in response to warming temperatures. This fragmentation is particularly damaging in subalpine and alpine zones, where suitable habitat is already compressed into narrow elevational bands; roads eliminate the connectivity that allows species to track climate-suitable conditions. Once fragmented, these high-elevation populations become trapped in warming refugia with no escape route, making local extinction likely as climate conditions exceed species' thermal tolerances.

Disruption of Ungulate Migration and Increased Mortality

Roads bisect the Wyoming Range mule deer and Sublette antelope migration corridors, creating barriers that force animals into longer, more circuitous routes and increase exposure to vehicle strikes during seasonal movements. Road construction also opens previously inaccessible areas to hunting and poaching, increasing harvest pressure on populations already suffering 50% winter mortality. The fragmentation of migration habitat concentrates animals into smaller seasonal ranges, increasing disease transmission risk—particularly critical given chronic wasting disease confirmed at nearby feedgrounds. For a mule deer population in demographic crisis, road-induced mortality and habitat compression would accelerate population decline.

Invasive Species Establishment and Loss of Native Plant Communities

Road construction creates disturbed corridors—exposed soil, compacted edges, and altered hydrology—that are rapidly colonized by cheatgrass, ventenata, and noxious weeds already identified as major threats in the West Slope Winds area. These invasive species outcompete native forage and understory plants, reducing food availability for grizzly bears, ungulates, and native pollinators including Suckley's cuckoo bumble bee (proposed endangered) and monarch butterfly (proposed threatened). The fire-invasive feedback loop documented in the area—where burned areas are immediately colonized by cheatgrass—is accelerated by roads, which increase fire ignition risk and create corridors for invasive seed dispersal. Once established, these monocultures are extremely difficult to reverse and persist for decades.

West Slope Winds spans 143,252 acres of subalpine and montane forest across the Bridger-Teton National Forest in Wyoming. The area encompasses the Sweetwater Needles (10,321 ft), Sioux Pass (9,450 ft), and Irish Canyon (8,400 ft), with access via trailheads at Big Sandy, Sweetwater, Green River Lake, Boulder Lake, and multiple cross-country ski areas. Over 60 maintained trails connect high-country lakes, ridges, and stream drainages throughout the roadless area.

Hunting

The West Slope Winds area is part of the Pinedale Elk Herd Unit and supports elk, mule deer, pronghorn, grizzly bear, black bear, mountain lion, bighorn sheep, and moose. Elk seasons are managed under the Pinedale Elk Herd Feedground Management Action Plan to maintain populations around 1,900 animals. The Scab Creek Elk Feedground, located on the western slope of the Wind River Range, is a key management site within or adjacent to the roadless area. Pronghorn hunting in Hunt Area 85 was closed for 2023–2025 due to winter mortality and disease. Greater Sage-Grouse are documented in the area. Hunters should submit harvested deer heads for Chronic Wasting Disease testing. Access points include Scab Creek, Sioux Pass, Sweetwater Needles, and Irish Canyon. The roadless condition preserves the remote backcountry character essential to hunting these species across unfragmented habitat.

Fishing

The Big Sandy River, East Sweetwater River, Dutch Joe Creek, Lander Creek, Sagebrush Creek, and North Fork Silver Creek support Colorado River Cutthroat Trout, Golden Trout, brook trout, rainbow trout, and brown trout. The Wyoming Game and Fish Department stocks Golden Trout by helicopter every two years in alpine lakes where natural reproduction is limited. Streams in the Green River Drainage (Area 4) have a creel limit of three trout per day; no more than one may exceed 16 inches, and no more than one cutthroat may exceed 12 inches. Many headwater streams are restricted to artificial flies and lures only. Live baitfish are prohibited in the Big Sandy drainage upstream of Big Sandy Reservoir. Anglers are encouraged to practice catch-and-release for native cutthroat trout. Primary access is via the Big Sandy Trailhead, Sweetwater Trailhead, and Dutch Joe Road. The area is renowned for small-stream fly fishing in remote alpine lakes and high-altitude rivulets. These cold headwater streams and their native trout populations depend on the roadless condition—roads would fragment habitat and degrade water quality in streams that support species of greatest conservation need.

Birding

The area supports Whooping Cranes (Endangered), Bald Eagles, Golden Eagles, Greater Sage-Grouse, Clark's Nutcrackers, Mountain Chickadees, Dark-eyed Juncos, and American Dippers. Spring and summer bring Yellow-rumped Warblers, Yellow Warblers, Mountain Bluebirds, White-crowned Sparrows, Western Meadowlarks, and Sandhill Cranes. The area serves as a migration corridor for waterfowl and shorebirds including Green-winged Teal and Killdeer. Winter residents include Northern Goshawks and various finches. The Pinedale Christmas Bird Count circle is the closest established count to the area. The Continental Divide National Scenic Trail, with approximately 15 miles being relocated to the Bridger-Teton National Forest in this vicinity, provides non-motorized backcountry access suitable for birding. The Absaroka Ridge Trailhead provides access to montane and subalpine species in the southern portion of the roadless area. Interior forest habitat and undisturbed stream corridors that support warblers, dippers, and other songbirds would be fragmented by road construction.

Photography

Sweetwater Needles and Blair Creek offer outstanding views in all directions. Sioux Pass and the southern Wind River Range provide scenic vistas of scoured bedrock. Boulter Lake is a documented scenic location. The Sweetwater River headwaters and Big Sandy River corridor are significant scenic and hydrological features. The area contains extensive wildflower parks; spring blooms in sagebrush steppe include arrowleaf balsamroot, scarlet gilia, silvery lupine, and low larkspur. Wet meadows and riparian corridors feature elephant's-head lousewort and other riparian species. High-elevation areas support alpine flora including Ross' avens, sky pilot, and yellow alpine flowers. Grizzly bears, wolves, moose, pronghorn, and Greater Sage-Grouse provide wildlife photography opportunities in sagebrush habitat. The interior of the roadless area maintains natural night sky conditions suitable for stargazing. Roads would introduce light pollution, vehicle traffic, and human activity that would degrade both wildlife viewing opportunities and the quiet, undisturbed character that makes photography here distinctive.