Borah Peak

The Borah Peak roadless area encompasses 130,463 acres across the Lost River Range in the Salmon-Challis National Forest, with elevations ranging from lower canyons to the 12,662-foot summit of Borah Peak itself. The landscape is defined by a series of high peaks—Leatherman Peak, Mount Breitenbach, and Donaldson Peak all exceed 12,000 feet—separated by passes and deep drainages including Sawmill Gulch, Hell Canyon, and Mahogany Gulch. Water originates in the alpine zone and flows downslope through multiple drainages: the Upper Dry Creek headwaters feed into Dry Creek, while the Pahsimeroi River system—including the East Fork and West Fork Pahsimeroi River—drains the western and southern portions of the area. Big Creek, Mahogany Creek, and Rock Creek complete the hydrologic network, each carrying snowmelt and groundwater from the high country to lower elevations.

Forest composition shifts dramatically with elevation and aspect. At lower elevations and on warmer exposures, Douglas-fir (Pseudotsuga menziesii) and curlleaf mountain mahogany (Cercocarpus ledifolius) dominate open woodlands with bluebunch wheatgrass (Pseudoroegneria spicata) and mountain big sagebrush (Artemisia tridentata ssp. vaseyana) in the understory. As elevation increases, Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) become prevalent, creating dense subalpine forest. The threatened whitebark pine (Pinus albicaulis) and limber pine (Pinus flexilis) occupy the highest elevations and windswept ridges, often in association with common juniper (Juniperus communis). Alpine meadows above treeline support low fleabane (Erigeron humilis), Kotzebue's grass-of-Parnassus (Parnassia kotzebuei), and snow willow (Salix nivalis)—species adapted to brief growing seasons and extreme exposure.

The area supports a diverse array of wildlife across its elevation zones. In alpine and subalpine habitats, mountain goats (Oreamnos americanus) and bighorn sheep (Ovis canadensis) navigate steep terrain, while American pikas (Ochotona princeps) inhabit talus fields where they forage and cache vegetation. The federally threatened North American wolverine (Gulo gulo luscus) ranges across high-elevation forests and meadows as a solitary predator. Golden eagles (Aquila chrysaetos) hunt from above, and the black rosy-finch (Leucosticte atrata), endangered (IUCN), forages on alpine slopes. Lower elevations support mule deer (Odocoileus hemionus) and pronghorn (Antilocapra americana) in sagebrush and grassland communities. The federally threatened bull trout (Salvelinus confluentus) inhabits cold-water streams throughout the drainage system, with critical habitat designated in the Pahsimeroi River and its tributaries. The proposed endangered Suckley's cuckoo bumble bee (Bombus suckleyi) pollinates alpine and subalpine wildflowers, while the proposed threatened monarch butterfly (Danaus plexippus) passes through during migration.

A person traveling through this landscape experiences distinct transitions in vegetation and terrain. Ascending from lower canyons like Hell Canyon or Mahogany Gulch, the forest shifts from open Douglas-fir woodland to increasingly dense subalpine spruce-fir forest, with the understory darkening and the sound of running water from tributary streams becoming more prominent. As the trail climbs toward passes like Leatherman Pass at 10,500 feet, trees become shorter and more widely spaced, and the canopy opens to reveal alpine meadows with low herbaceous plants. The final approach to high peaks crosses windswept ridges where whitebark pine and limber pine grow in stunted, contorted forms, and the landscape opens to bare rock and scree. Throughout the area, the presence of water is constant—from the roar of creeks in narrow canyons to the trickle of snowmelt seeping through alpine meadows—shaping both the vegetation and the movement of wildlife across the terrain.

Indigenous peoples of the Northern Shoshone and Bannock nations inhabited the region encompassing present-day Borah Peak for over 10,000 years, as evidenced by archaeological sites throughout the Salmon-Challis National Forest containing spear points and lithic scatters. These groups practiced a seasonal round, wintering in lower-elevation valleys and moving into high-mountain areas like the Lost River Range during summer and early fall to hunt big game including mountain sheep, elk, and deer. Native Americans in central Idaho historically used fire as a management tool to clear trails, improve forage for game, and regenerate meadows. The Lemhi Valley Indian Reservation was established by executive order of President Ulysses S. Grant in 1875 for mixed tribes of Shoshone, Bannock, and Sheapeater Indians. Today, the Shoshone-Bannock Tribes of the Fort Hall Reservation maintain off-reservation treaty rights to hunt, fish, and gather on these ancestral lands, including the Salmon-Challis National Forest.

European settlement in the region began with the establishment of the Salmon River Mission (Fort Lemhi) from 1855 to 1858, when Mormon missionaries established a settlement to proselytize the Shoshone. The town of Challis was established in 1876 as a supply depot for surrounding mining and livestock operations. Leadore was established in 1904 near Gilmore Summit and flourished as a railroad hub, becoming the primary community in the upper Lemhi Valley. Mining activity in the vicinity began with claims recorded in the early 1880s, including the Inter-Ocean lode (1892), the Golden Rule lode (1897), and by 1918, the Mineral King, Mineral Queen, and Twin Falls claims. Despite this early prospecting, the area has no known economic metallic mineral resources. The nearest industrial hubs were Mackay, sixteen miles south, which served as a major copper mining center and terminus of a Union Pacific Railroad spur from 1901 to 1931, and Challis, thirty-eight miles north.

The Salmon River Forest Reserve was established on November 5, 1906, by proclamation of President Theodore Roosevelt under the authority of the Forest Reserve Act of 1891 and the Organic Administration Act of 1897. The reserve was renamed the Salmon National Forest on July 1, 1908, through Executive Order 841 issued by President Roosevelt, which also added lands from the Bitterroot Forest Reserve (established 1897) and the Lemhi National Forest. The Challis National Forest was simultaneously established on July 1, 1908, by executive order of President Roosevelt. Subsequent presidential proclamations modified forest boundaries: in 1913, President Woodrow Wilson adjusted boundaries between the Salmon, Challis, Lemhi, and Sawtooth National Forests; in 1926, President Calvin Coolidge transferred land west of the Middle Fork of the Salmon River to the Salmon National Forest; in 1930, President Herbert Hoover transferred the North Fork of Morgan Creek drainage from the Salmon National Forest to the Lemhi National Forest; and in 1940, Executive Order No. 8355 transferred additional lands from the Idaho National Forest to the Salmon National Forest. The Salmon and Challis National Forests were administratively combined in a USDA pilot program launched in 1996 and formally approved in February 1998, streamlining management of the consolidated unit.

On October 28, 1983, a magnitude 6.9 earthquake—the largest recorded in Idaho's history—struck the region. The event resulted in two fatalities in the nearby town of Challis and approximately $12.5 million in property damage. The quake caused the Lost River Range to rise by approximately one foot, the Thousand Springs Valley to drop by as much as fourteen feet, and created a twenty-one-mile surface fault scarp along the western base of the range with vertical displacements up to nine feet.

In 1980, the Central Idaho Wilderness Act (Public Law 96-312) established the Frank Church–River of No Return Wilderness, which encompasses 2.36 million acres across six national forests, including a significant portion of the Salmon-Challis. The Borah Peak area is designated as an Inventoried Roadless Area within the Salmon-Challis National Forest and is managed by the Lost River Ranger District.

Vital Resources Protected

Alpine Climate Refugia for Threatened Carnivores

The Borah Peak area's high-elevation terrain—with peaks exceeding 12,600 feet and persistent spring snowpack—provides critical denning and movement habitat for the federally threatened North American wolverine. Wolverines depend on areas with reliable deep snow for maternal denning; climate projections indicate suitable wolverine habitat in the region will shrink by 63% by 2100 due to warming and snowpack loss. This roadless area currently functions as one of the few remaining high-elevation corridors where wolverines can access the persistent snow conditions necessary for reproduction, making it essential to their survival as climate change narrows their range.

Headwater Protection for Cold-Water Fish

The Borah Peak area contains the headwaters of the Pahsimeroi River system and Upper Dry Creek, which feed downstream spawning grounds for federally threatened bull trout and Chinook salmon. Bull trout require cold, clean water and intact riparian buffers; the area's roadless condition preserves the natural forest canopy that shades these streams and maintains the low temperatures these species need to survive. Downstream, spawning habitat for Chinook salmon has already declined 23% over six decades due to warming and reduced flow—the headwater streams in this roadless area represent irreplaceable thermal refugia that buffer against further temperature increases and maintain the cold-water connectivity these fish require.

Whitebark Pine High-Elevation Forest

Whitebark pine, a federally threatened species, occurs throughout the subalpine zone of the Borah Peak area and provides critical food for grizzly bears, wolverines, and other wildlife. The roadless condition protects these trees from the direct disturbance and edge effects that accelerate white pine blister rust infection and mountain pine beetle outbreaks. Once roads fragment whitebark pine forests, the resulting canopy gaps and warmer microclimates create conditions favoring both the rust pathogen and beetle populations—losses that are difficult to reverse in high-elevation systems with slow tree growth and limited regeneration capacity.

Pollinator and Songbird Habitat in Intact Subalpine Meadows

The area's alpine and subalpine meadows support populations of Suckley's cuckoo bumble bee (proposed endangered) and black rosy-finch (IUCN endangered), species dependent on unfragmented native wildflower communities and open alpine terrain. The roadless condition maintains the continuous native plant cover and absence of invasive species that these specialists require; road construction and the soil disturbance it causes create entry points for invasive species that outcompete the native forbs and grasses these pollinators and birds depend on for food and nesting habitat.

Threats from Road Construction

Sedimentation and Stream Temperature Increase from Canopy Removal

Road construction in steep terrain requires cut slopes and removal of riparian forest to accommodate roadbeds and drainage. In the Borah Peak area's mountainous landscape, these cuts expose unstable soils to erosion; sediment from construction and chronic erosion along the roadbed will wash into headwater streams, smothering the clean gravel spawning substrate that bull trout and Chinook salmon require. Simultaneously, removal of the forest canopy along stream corridors eliminates shade, causing water temperatures to rise—a direct threat to bull trout, which are already losing thermal refugia to climate warming and cannot tolerate the temperature increases that road-adjacent streams experience.

Habitat Fragmentation and Loss of Wolverine Denning Connectivity

Road construction fragments the continuous high-elevation terrain that wolverines use to move between denning areas and across the landscape in search of food. Wolverines avoid roads and developed areas; the presence of a road network breaks the unfragmented alpine habitat into isolated patches, preventing females from accessing suitable denning sites and reducing genetic connectivity between populations. In a landscape where suitable denning habitat is already projected to shrink 63% by 2100, road-induced fragmentation accelerates the isolation of remaining populations and makes the area unable to function as a climate refuge or dispersal corridor.

Invasive Species Establishment Along Road Corridors

Road construction creates disturbed soil and compacted edges that serve as entry points for invasive species, particularly cheatgrass in the sagebrush and grassland zones of the Borah Peak area. Cheatgrass establishes readily in road cuts and shoulders, then spreads into adjacent native meadows where it outcompetes the native wildflowers that Suckley's cuckoo bumble bee and other pollinators depend on. Once cheatgrass dominates, it increases fire frequency and severity, creating a self-reinforcing cycle that converts native subalpine and alpine plant communities to invasive grassland—a transformation that is extremely difficult to reverse in high-elevation systems with short growing seasons.

Culvert Barriers and Loss of Aquatic Connectivity

Road crossings of streams require culverts or bridges; improperly designed culverts create barriers that prevent bull trout and other fish from moving upstream to access cold-water refugia and spawning habitat. In a headwater system like the Pahsimeroi River drainage, where bull trout populations are already fragmented and dependent on access to the coldest available water, culvert barriers eliminate critical thermal refuge areas and prevent fish from shifting their distribution in response to warming—a particularly acute threat given that stream temperatures in this region are already rising due to climate change and reduced snowpack.

The Borah Peak Roadless Area spans 130,463 acres across the Lost River Range in the Salmon-Challis National Forest. At its center stands Borah Peak (12,662 ft), Idaho's highest point, surrounded by alpine terrain that supports a range of backcountry recreation. The area's roadless condition—maintained by the absence of motorized access on most trails—defines the character of recreation here: quiet, undisturbed watersheds, unfragmented habitat for wildlife, and trails where hikers, horseback riders, and hunters encounter the landscape on foot or horseback rather than from a vehicle.

Hiking and Climbing

The Borah Peak Trail (#4044) is the primary draw for climbers and hikers. This 3.5-mile ascent gains 5,400 feet and is rated as a black diamond climb due to extreme steepness and technical sections. The route includes Chicken Out Ridge, an 11,400-foot knife-edge requiring scrambling with hands and feet, and a second crux involving a 20-foot downclimb on a rock tower. Plan 6–12 hours round-trip; the climbing season runs from early July through mid-August to avoid snow. No permits are required, though a $5 fee applies for camping at the Mt. Borah Trailhead and Camping Area.

For less technical hiking, the Leatherman Pass Trail (#4089) offers an easy 5.7-mile route that follows Little Creek through slide rock to the 10,500-foot pass, with views of the West Fork Pahsimeroi River. The Merriam Lake Trail (#4197) is a strenuous 1.8-mile hike gaining 1,366 feet through subalpine forest and wildflower meadows to a glacial lake, with small waterfalls along the route. The Swauger Lake Trail (#4091) is rated easy to intermediate at 6.1 miles, climbing steeply along a ridge with views of the Lost River Range and colorful rock formations.

Horseback riders have access to multiple trails: Leatherman Pass (#4089), Massacre Creek (#4090), Swauger Lake (#4091), East Fork Upper Pahsimeroi (#4199), Pass Lake (#4198), Bear Creek Lake (#4092.1), Long Lost (#4194), Big Creek-Massacre (#4093), and Lower Cedar Creek (#4382). The West Fork Upper Pahsimeroi Trailhead provides primary access to the northern section. The Borah Peak Trail is hikeable for the first 3 miles but becomes impassable for bicycles beyond that point due to cliffs and large rocks.

Hunting

The roadless area overlaps Game Management Unit 50 (Lost River) and is part of the Lost River Elk Zone. Documented game species include elk, mule deer, bighorn sheep, mountain goat, moose, pronghorn antelope, black bear, mountain lion, and gray wolf. Upland birds include greater sage-grouse, forest grouse (dusky, ruffed, and spruce), chukar, and gray partridge. Small game includes pygmy rabbits and squirrels.

General deer season in Unit 50 typically runs in October; archery and muzzleloader seasons begin August 30. Sage-grouse hunting requires a specific tag and occurs in September. Pronghorn antelope, bighorn sheep, moose, and mountain goat are managed through controlled hunt permits. All hunters of deer, elk, pronghorn, bighorn sheep, moose, and mountain goat must submit mandatory harvest reports. As of 2025, all bear hunters must complete a mandatory bear identification course.

The Borah Peak Trailhead (on Birch Springs Road between mileposts 129 and 130 on U.S. Highway 93, approximately 21 miles north of Mackay) provides primary access to the high-elevation central section. Double Springs Pass and Pass Creek Summit are the only two roads crossing the Lost River Range crest and provide access to the northern and southern portions. The BLM Challis Field Office enacts seasonal motorized travel restrictions from October 1 through December 31 in certain areas to provide non-motorized hunting experiences. The roadless condition preserves the quiet, undisturbed character that defines backcountry hunting—hunters access the area on foot or horseback, not by vehicle, maintaining the integrity of the landscape and wildlife habitat.

Fishing

The Pahsimeroi River and its West Fork support rainbow trout, westslope cutthroat trout, and bull trout, and serve as critical spawning tributaries for anadromous chinook salmon and steelhead. The West Fork Pahsimeroi provides access to prime fishing grounds near high-elevation destinations like Merriam Lake and Pass Lake. Most trout species in the Salmon River and its upper tributaries reproduce naturally; management emphasizes protecting wild populations.

Bull trout are strictly catch-and-release statewide and must be released immediately without removal from the water. In Salmon River tributaries (excluding the main Pahsimeroi and East Fork), trout fishing is catch-and-release from December 1 through the Friday before Memorial Day weekend. Steelhead and salmon fishing is prohibited unless a specific season is opened by Idaho Fish and Game; when open, only hatchery fish (identified by a clipped adipose fin) may be kept. Single-pointed barbless hooks are required for salmon and steelhead.

Access to fishable waters is provided by the West Fork Upper Pahsimeroi Trailhead and the East Fork Upper Pahsimeroi Trail (#4199), which begins at the end of East Fork Road. The roadless condition preserves the solitude and untrammeled character of these waters—anglers reach them on foot or horseback, not by vehicle—and maintains the cold, undisturbed headwater streams that support wild trout populations and anadromous fish migrations.

Birding

The area is a documented breeding ground for the black rosy-finch, which nests in high-altitude alpine cirques, cliffs, and rock slides between 10,000 and 10,700 feet. Golden eagles and other raptors use thermals around Borah Peak for hunting and movement. Ravens are frequently observed catching thermals near the summit. The broader Lost River Range supports American dipper, Townsend's solitaire, pine grosbeak, Clark's nutcracker, and both species of crossbills.

During breeding season (June–August), black rosy-finches are active at high elevations; males sing in alpine cirques and females gather nesting material near snowfields in late June. The Lost River Range serves as a migration corridor; nearby wetlands like Chilly Slough and Mackay Reservoir (within 20 km) host large seasonal flocks of sandhill cranes, trumpeter swans, and waterfowl. The Borah Peak Trail provides primary access for observing alpine specialists and high-altitude raptors. The roadless condition preserves the quiet, undisturbed alpine habitat that black rosy-finches and other high-elevation species depend on for breeding and foraging.

Photography

Borah Peak's 12,662-foot summit offers 360-degree panoramic views across two dozen of Idaho's highest mountains and the valley below. Chicken Out Ridge, the narrow knife-edge at 11,300–11,800 feet, provides dramatic high-exposure vistas of surrounding alpine terrain and deep cirques. The Leatherman Peak and Donaldson Peak routes offer quality high-elevation vistas of the central Idaho wilderness. Lower Cedar Creek Falls, accessible via a 3-mile moderate trail, provides waterfall photography opportunities. Large glacial cirques ringed by cliffs are visible from the upper slopes of Borah Peak, often containing seasonal snow and ice features.

Alpine vegetation includes scattered mountain mahogany, sagebrush-grass communities on west-sloping terrain, and a distinct timberline at approximately 10,000 feet. Typical Idaho alpine wildflowers such as lupine and arrowleaf balsamroot peak from May through July. Mountain goats and bighorn sheep frequent the rocky ridges and peaks; elk, moose, and pronghorn roam the area. Golden and bald eagles are frequently viewed and photographed. The area is located in Custer County, which shares the high elevation and arid climate of the nearby Central Idaho Dark Sky Reserve, providing exceptional transparency for viewing the Milky Way and celestial events.