Unit 58, Idaho

The unit covers approximately 594 square miles (379,945 acres) at elevations ranging from roughly 6,000 feet in the Birch Creek Valley floor to over 12,000 feet along the Continental Divide ridgelines of the Beaverhead Mountains. Terrain transitions from gentle valley bottomlands through steep canyon walls to rugged high-country peaks, talus slopes, and rock slides. Most high-country terrain above 9,500 feet is open and roadless; a significant portion falls within the Italian Peaks roadless area along the Continental Divide.

The unit is accessed primarily via State Highway 28, which runs north-south through the Birch Creek Valley connecting Leadore to the north with Interstate 15 near Mud Lake/Idaho Falls to the south. The eastern high country falls within the Salmon-Challis National Forest; the mountains on the west side of the valley are administered by the Caribou-Targhee National Forest; valley floor and lower slopes are largely BLM (Upper Snake Field Office, Idaho Falls, 208-524-7500). A BLM campground (Birch Creek Campground) is located along Birch Creek off Highway 28. Most hunters camp along dirt roads branching off the highway into canyon drainages. There are no federally designated wilderness areas within the unit boundary. The high country above the valley is largely roadless (Italian Peaks roadless area). Motorized vehicle use by hunters is restricted to established roadways legally open to full-sized automobiles from August 30 through December 31. A corner of the Idaho National Laboratory (DOE-managed land, ~7.4% of the unit) in the southern portion is closed to hunting. The Birch Creek Area of Critical Environmental Concern has a motorized-use closure from December 16 through April 30.

The lower Birch Creek Valley and south-facing hillsides are dominated by sagebrush-steppe with forbs, native bunchgrasses, and scattered juniper and aspen. Mid-elevation slopes transition to mixed conifer at roughly 7,500 feet, with spruce, fir, and pine — especially dense on north-facing aspects. Above approximately 9,500 feet the forest gives way to open alpine terrain of rocky peaks, boulder fields, and grassy meadows. Land cover is approximately 69% rangeland and 28% forest (IDFG); roughly 2% irrigated agricultural land in the valley bottom.

Mule deer inhabit the unit year-round, using sagebrush-steppe and canyon terrain in the lower country and migrating to high alpine basins in summer; bucks seek dense north-slope timber as escape cover. Elk utilize the forested high country during summer and early fall and move to lower-elevation sagebrush and valley edges in winter; the unit is part of the Beaverhead Elk Zone (Units 30, 30A, 58, 59, 59A). Pronghorn are present on the open sagebrush benchlands in the valley and lower hills. White-tailed deer are present but rare (~3% of deer harvest). Black bear, mountain lion, moose, bighorn sheep, mountain goat, and gray wolf are also present. Sage-grouse, sharp-tailed grouse, chukar partridge, gray partridge, pheasant, and turkey are found in appropriate lower-elevation habitat.