Unit 56, Idaho

Unit 56 covers 578,411 acres of highly variable terrain. The South Hills (Cassia Mountains) feature smooth, rolling ridgelines and rounded dome summits; Monument Peak reaches 8,041 feet. The Black Pine Mountains rise to approximately 9,389 feet with steeper ridge sides. Lower terrain transitions into broad sagebrush flats and agricultural valleys, with base elevations around 4,500 feet near Rock Creek. Roughly 80% of public-land terrain has slopes of 22 degrees or less, making access comparatively forgiving. No designated wilderness areas exist within the unit.

Unit 56 is bounded by Yale Road/State Highway 81 to the northwest, Interstate 84/86 to the north and northwest, State Highway 37 to the east (near Holbrook), the Holbrook-Stone Road to the southeast, and the Idaho-Utah state line to the south. Primary federal land managers are the BLM Burley Field Office (~23.85% of unit) and the Sawtooth National Forest Minidoka Ranger District — Cassia and Black Pine Divisions (~13.61% USFS). The Caribou National Forest is also present. The Minidoka Ranger District maintains Motor Vehicle Use Maps (MVUMs) for the Cassia and Black Pine Divisions. The Rock Creek Complex south of Twin Falls offers eight campgrounds and 60 miles of trails accessed by three trailheads within the Cassia Division. A motorized hunting rule applies in Unit 56 from August 30 through December 31, restricting all big game hunters to established roadways legally open to full-sized automobiles. Private land constitutes about 51% of the unit; no Access Yes! properties are currently listed within Unit 56.

Vegetation transitions sharply with elevation. Lower elevations (4,500–6,000 ft) support sagebrush-steppe, pinyon-juniper, curl-leaf mountain mahogany, and saltbush on BLM and private agricultural land. Mid-elevations carry aspen groves, sagebrush parks, and mountain shrub communities. Upper forested slopes on the Sawtooth and Caribou NFs feature lodgepole pine, subalpine fir, and Douglas-fir, with open meadows and riparian draws. Land use: dryland agriculture ~42%, rangeland ~37%, forest ~13%, irrigated lands ~7%.

Mule deer are the primary big game species with a migratory population using high-elevation summer range in the forested South Hills and Black Pine Mountains, descending to low-elevation sagebrush-steppe and agricultural winter range. Elk inhabit the timbered South Hills and are managed under the South Hills Elk Zone (units 46, 47, 54, 55, 56, 57). Pronghorn occupy the open sagebrush-steppe and rangeland portions, particularly lower BLM lands around the Cotterel, Deep Creek, and Black Pine foothills. Mountain lion and gray wolf are present and huntable. Moose are listed as a huntable species. Upland birds include sage-grouse, chukar, quail, pheasant, sharp-tailed grouse, gray partridge, dove, and forest grouse.