This area located south of Challis has some of the highest bighorn sheep habitat in Idaho that can be found in the Sawtooth National Recreation Area, the Boulder Mountains and other parts of the Salmon River Mountains.

Hunter success can be improved by scouting and hunting for many days to kill a mature ram. The terrain in this area can be physically demanding.

This unit stretches all the way from U.S. Highway 93 to the Sawtooth Valley. Sheep live in the mountains that run north and south through the unit, which is entirely in Custer County. The terrain in this area has some of the highest and most rugged mountains in the state, including the Boulder Mountain Range and White Cloud Peaks. The high country is in the Challis and Sawtooth National Forests, while most of the middle-elevation and low land is managed by the BLM. Some high points exceed 11,000 feet in elevation, including Castle Peak, Easley Peak, Galena Peak, Glassford Peak, Silver Peak and Ryan Peak. The mountains contrast desert flats and low foothills where sheep rarely wander.

Road access starts from U.S. Highway 93 southeast of Challis and Idaho Route 75 in the southwest. Many interior roads intersect the main routes like Bradbury Flat Road, Spar Canyon Road and East Fork Road. The northern and eastern parts of the unit are primarily BLM land, while the Salmon Challis National Forest controls land in the south and east. Private lands are farm fields and pastures along the main roads and lowland creeks and rivers. Beaver Creek Road outside the unit gives access to Boulder Peak near Silver Peak.

Sheep are rarely found in the western and northern parts of this area which are made up of low foothills and desert flats covered with sagebrush and wild grasses. Willows and cottonwoods line much of the Salmon River and fields planted in grass hay, alfalfa and other crops are along the river and Warm Springs Creek. Aspens grow in some foothill draws. Mahoganies, bitterbrush, serviceberries, river birch and alders grow in places throughout the unit. Pines and firs grow on north and east-facing slopes above 7,000 feet and on most slopes above 8,000 feet. Sheep live mainly in the higher parts of this area and above timberline at 8,000 feet. Bighorns usually enter sparse spruces, firs and pines but rarely hide or feed in dense timber. Sheep can typically be seen feeding close to timberline or above timberline on lichens, grasses, mosses, willows, wildflowers and forbs.

Hunters can camp along dirt roads or pack tents into the backcountry by horse or foot. Several primitive campgrounds are found along Idaho Route 75 with a couple of private facilities. The BLM has a primitive Herd Lake campsite and overlook below Herd Lake. Another primitive campsite is on the East Fork Road just north of the mouth of Germania Creek. Lodging is available in Challis