Gannett Hills - Spring Creek

The Gannett Hills - Spring Creek roadless area covers 45,462 acres of the Bridger-Teton National Forest along the Wyoming–Idaho line, with terrain defined by the rolling Gannett Hills, the sharp profile of The Pinnacle, and the broad opening of Allred Flat below Salt River Pass. Salt Canyon and Salt Basin reach into the southern half of the area. Water is a major resource: Spring Creek heads in the southern hills, and twenty named tributaries — Salt Creek, the numbered drainages from First through Sixth Creek, Robinson Creek, Dip Creek, Driveway Creek, Lost Creek, Christopherson Creek, Sprague Creek, Willow Creek, and others — gather into the Bear River system. The North Fork Fish Creek and Packstring Creek drain east toward the Salt River.

The area's plant communities range across an exceptional elevational and moisture gradient. Below the hills, Great Basin Big Sagebrush Steppe and Intermountain Mountain Sagebrush Steppe cover the open slopes with big sagebrush (Artemisia tridentata), rubber rabbitbrush (Ericameria nauseosa), arrowleaf balsamroot (Balsamorhiza sagittata), and northern mule's-ears (Wyethia amplexicaulis). Central Rockies Douglas-fir Forest fills the mid-slopes alongside extensive Rocky Mountain Aspen Forest, where quaking aspen (Populus tremuloides) rise above sticky geranium (Geranium viscosissimum) and clustered leatherflower (Clematis hirsutissima). Higher up, Rocky Mountain Lodgepole Pine Forest gives way to Rocky Mountain Dry Subalpine Spruce-Fir Forest carrying subalpine fir (Abies lasiocarpa) with Wasatch beardtongue (Penstemon cyananthus) and Oregon boxleaf (Paxistima myrsinites) in the understory. Rocky Mountain Subalpine Meadow and Northern Rockies Subalpine Grassland open the highest benches, with scattered Rocky Mountain Limber and Bristlecone Pine Woodland on the windswept ridges.

The Spring Creek drainage holds native Rocky Mountain cutthroat trout (Oncorhynchus virginalis) and the Bonneville sculpin (Cottus semiscaber), the latter restricted to Bonneville Basin tributaries; redside shiner (Richardsonius balteatus) shoals through the larger pools. American beaver (Castor canadensis) build dams on the willow-fringed tributaries, raising water tables that support moose (Alces alces) browse. Wapiti (Cervus canadensis), mule deer (Odocoileus hemionus), and snowshoe hare (Lepus americanus) move through the aspen-conifer mosaic; the white-tailed jackrabbit (Lepus townsendii) holds the sage-steppe edges. Osprey (Pandion haliaetus) and red-tailed hawk (Buteo jamaicensis) hunt the open country; sharp-tailed grouse (Tympanuchus phasianellus) lek in sage; dusky grouse (Dendragapus obscurus) drum in conifer cover. White-faced ibis (Plegadis chihi) work the wetter margins. Portions of this area fall within the potential range of several federally listed species; see the Conservation section for details.

A traveler on the State Line Trail follows the Wyoming–Idaho border 14.3 miles through the heart of this country, while the Spring Creek Divide Trail and Gannett Hills Trail cross the ridge corridors above the headwater basins. From the Spring Creek–State Line trailhead the route climbs through sagebrush into aspen and lodgepole. Salt River Pass and the rim of The Pinnacle offer long views across Salt Canyon toward the Caribou Range to the west. In winter the same country becomes the Salt River Pass and Fish Creek cross-country ski corridors.

The Gannett Hills - Spring Creek country, straddling the Wyoming–Idaho line in Lincoln and Caribou counties, has been a hunting ground for thousands of years. Archaeological evidence on the Bridger-Teton National Forest documents human occupation for the past 10,000 years, with more than 800 prehistoric and historic sites recorded across the forest [1]. The Shoshone were the primary inhabitants of present-day Lincoln County before the 1820s, gathering roots, berries, and small game and pursuing larger animals when conditions allowed [3]. After horses reached the region in the early 1700s, Northern Paiute bands left the Nevada and Utah basins for southern Idaho and joined the Shoshones on cooperative buffalo hunts into Montana, becoming known as the Bannocks; the last great hunt of this type occurred in 1864 [4]. In 1868, the Shoshones and Bannocks signed the Fort Bridger Treaty, which established the Fort Hall Reservation on the Snake River Plain north of present-day Pocatello [4].

European fur trappers entered the region in the early 1800s. The Greys River, which drains the eastern flank of the Gannett Hills, takes its name from one of those early trappers; the Hoback, Fontenelle, LaBarge, Smiths Fork, and Hams Fork were all named in the same era [1]. In 1812, the Astorian party led by Robert Stuart traveled east from the mouth of the Columbia through the mountains and valleys of what is now northern Lincoln County [3]. Beaver trapping continued until the market collapse around 1840. In 1857, federal engineer Frederick W. Lander surveyed the Lander Cutoff, the first federally funded road project west of the Mississippi, which crossed the southern margins of the Wyoming and Salt River Ranges on its way from South Pass toward Fort Hall in Idaho; in its first year of use, over 13,000 emigrants traveled the road [1].

White settlement of the Star Valley to the south and west of the Gannett Hills began in the 1870s. Trapper John Welsh and an unnamed companion built a cabin in the valley in 1874, though they stayed only a couple of years [3]. Permanent settlement began in 1878 when members of the Church of Jesus Christ of Latter-day Saints arrived from Utah, seeking remote land after the 1874 Poland Act intensified federal prosecution of polygamy; they founded the town of Afton and built dairy farms and creameries throughout the valley [3]. The Rock Church at Auburn, built of local stone in 1889, remains as a landmark of this settlement era [2].

Federal forest administration arrived in the Progressive Era. President Theodore Roosevelt established the Yellowstone Forest Reserve in 1902, and in 1908 he abolished it, creating the Teton, Wyoming, Shoshone, Bonneville (now Caribou), and Targhee National Forests in its place [1]. The Wyoming National Forest, which included the Greys River country and the Gannett Hills, was renamed the Bridger National Forest in 1941; in 1973 the Bridger and Teton National Forests were administratively combined to form the Bridger-Teton [1]. Lincoln County itself was created in 1911 from Uinta County, with Kemmerer as the county seat [3]. The 45,462-acre Gannett Hills - Spring Creek roadless area lies within the Greys River Ranger District and is protected today under the 2001 Roadless Area Conservation Rule.

Vital Resources Protected

• Cold-Water Stream Integrity. The Spring Creek drainage and its twenty named tributaries supply cold, sediment-free water to the Bear River system, which flows ultimately to the Great Salt Lake. The roadless condition protects spawning habitat for native Rocky Mountain cutthroat trout and Bonneville sculpin (Cottus semiscaber), a species restricted to Bonneville Basin streams and dependent on intact gravel substrates. Healthy headwater channels also support American beaver populations whose dam-building maintains the willow wetlands used by moose and a range of riparian birds.

• Unfragmented Sagebrush-Aspen-Conifer Connectivity. Sagebrush steppe occupies more than 30 percent of this 45,462-acre tract, transitioning seamlessly into aspen and Douglas-fir on the upper slopes. The unbroken transition is the kind of mosaic that sharp-tailed grouse (Tympanuchus phasianellus) require for leking, brood-rearing, and winter cover, and that wapiti, mule deer, and moose use as connected seasonal range. The intact sagebrush blocks also limit conversion to invasive cheatgrass (Bromus tectorum) and dyer's woad (Isatis tinctoria), both documented in the area as threats to native vegetation.

• Movement Corridor for Wide-Ranging Carnivores. The area lies within the potential range of federally threatened Canada lynx, grizzly bear, and North American wolverine. The roadless condition maintains an unbroken north-south corridor along the Wyoming–Idaho border that connects the Caribou Range to the west with the Salt River Range and Wyoming Range to the east. Continuous habitat without road-related disturbance supports den security, prey availability, and dispersal — particularly for lynx, whose recovery depends on contiguous boreal-zone forest with deep, persistent snow.

Potential Effects of Road Construction

• Sedimentation and channel disruption. Road construction on the rolling slopes above Spring Creek and its named tributaries would deliver chronic sediment from cut slopes and ditch lines into spawning gravels, embedding the substrate cutthroat trout and Bonneville sculpin require for reproduction. Stream crossings without canopy elevate summer water temperatures above the thermal tolerance of native cold-water species, and channel rerouting at culverts breaks the continuous riffle-pool structure essential to aquatic invertebrate production.

• Sagebrush conversion and invasive spread. Road corridors are the primary vector for cheatgrass, dyer's woad, smooth brome (Bromus inermis), and musk thistle (Carduus nutans) in the Intermountain West; ditches and cut banks provide continuous disturbed soil for establishment, and traffic carries seed across the landscape. Once these invasives colonize sagebrush steppe, they alter fire-return intervals and out-compete native bunchgrasses, converting habitat used by sharp-tailed grouse and big game into monocultures of low forage value that resist active restoration.

• Carnivore corridor fragmentation. Permanent road surfaces fragment the unbroken aspen-conifer interior that lynx, wolverine, and grizzly bear require for seasonal movement and den security. Roads introduce direct mortality from vehicle strikes, increase human access for incidental encounters, and create edge effects — drying, noise, predator concentration — that extend hundreds of meters into adjoining cover. For wide-ranging species already at low population density, a single permanent road can sever connectivity that took millennia to establish.

The Gannett Hills - Spring Creek area carries an extensive hiker and horse trail network on Bridger-Teton National Forest land. The State Line Trail (3026), 14.3 miles of native-material tread, follows the Wyoming–Idaho border the length of the area for hiker and horse use, with the Spring Creek (West Side) Trail (3027) adding 12.1 miles to the west and the Salt Basin Trail (3534), 10.0 miles, opening the southern half to horse parties. The Spring Creek Divide Trail (3589), 9.0 miles, is open to horse and mountain-bike use; the Gannett Hills Trail (3046) and Gannet Ridge Trail (3580) follow the ridge crests, with the North Fork Fish Creek Trail (3023, 7.4 miles), Water Canyon Trail (1030, 4.9 miles), Packstring Creek Trail (1032, 4.0 miles), Giraffe Creek Trail (3518, 2.9 miles), and shorter Second Creek Trail (3028, 0.8 miles) giving foot access into the drainages. Principal access is the Spring Creek–State Line Trailhead.

Allred Flat Campground provides developed camping on the southern edge of the area, near Salt River Pass. Beyond Allred Flat, dispersed backcountry camping is permitted on national forest land throughout the area, with no designated sites required. The long State Line, Spring Creek, and Salt Basin Trails support multi-day backpacking and pack trips through aspen meadows and subalpine basins.

Cold-water angling is supported in Spring Creek and its named tributaries — Salt Creek, Robinson Creek, Lost Creek, Christopherson Creek, Sprague Creek, and the numbered First through Sixth Creeks — which hold native Rocky Mountain cutthroat trout (Oncorhynchus virginalis), Bonneville sculpin (Cottus semiscaber), and redside shiner (Richardsonius balteatus). Big-game hunting under Wyoming Game and Fish Department regulations is supported on the surrounding national forest land, with wapiti (Cervus canadensis), mule deer (Odocoileus hemionus), and moose (Alces alces) as primary species pursued in season. Sharp-tailed grouse (Tympanuchus phasianellus) provide upland bird hunting in the sage-steppe edges. Hunters and anglers enter on foot or horseback from the Spring Creek–State Line trailhead, carrying gear without motorized assistance.

Winter recreation centers on three marked cross-country ski corridors. The Salt River Pass Cross-Country Ski Trail (3XC188), 1.8 miles, and the Salt River Pass Spur (3XC188A), 1.4 miles, give skiers access to the Salt Basin from the pass; the Fish Creek Cross-Country Ski Trail (3XC187), 4.0 miles, threads the drainage below. The Smiths Fork Snowmobile Trail (3SM10072), 6.1 miles, provides oversnow access on the southern flank of the area, entered from the Smiths Fork Snowmobile Trailhead. The Fish Creek Cross-Country Ski Trailhead South is the principal skier access.

The Canyon View Park and Trail eBird hotspot, the most active site within 24 km, has recorded 80 species across 77 checklists. Sharp-tailed grouse leks, white-faced ibis foraging on wet meadows, and osprey on the riparian corridors give birders specific targets. Photographers find subject matter in the aspen colonies during fall color, on the open Allred Flat meadows under Salt River Pass, and on the long views from The Pinnacle.

Every supported activity here depends on the area's roadless condition. The 14.3-mile State Line Trail's value as a long border ride or hike depends on the absence of road crossings. Cold-water angling depends on the sediment-free streams produced by intact slopes. Big-game hunting and sharp-tailed grouse lekking depend on unfragmented sagebrush and aspen-conifer range. Winter cross-country ski corridors at Salt River Pass and Fish Creek hold their character only because no plowed road runs through the country.