Unit 72, Idaho

Unit 72 is characterized by low mountain ranges and rolling terrain with elevations generally between 4,700 and 7,800 feet. Nearly all ridges and peaks remain below 7,000 feet, with only a few barely exceeding that mark. Interspersed between the ranges are flat to gently sloping dry-farm fields, irrigated meadows, and short foothills. The Portneuf Mountains at the unit's western edge rise from roughly 4,700 feet along the Portneuf River to timbered ridgelines approaching 7,500 feet. Deep draws and brush-covered slopes are common throughout.

Unit 72 contains no National Forest lands and no designated Wilderness areas. Public land totals approximately 43% of the unit per IDFG (BLM 9.3%, Idaho State 21.85%, BIA/Fort Hall Indian Reservation 10.22%, other 1.78%); private land is 56.84%. BIA/tribal land is not open to non-tribal hunters, making accessible public land closer to 36%. Some private parcels block direct road access to public sections. Key boundary roads include State Highway 34 along the Blackfoot River, Government Dam Road along the Blackfoot Reservoir shoreline, Government Dam–Fort Hall Road to the Portneuf River, Chesterfield-Bancroft Road, and the Pebble-Bancroft county road (former U.S. 30N). Camping on BLM and state land is available near Twentyfour Mile Reservoir. The Portneuf Wildlife Management Area (3,950 acres, Bannock County) provides additional public access with eleven miles of primitive roads; motorized access on the Portneuf WMA is restricted November 15 through May 15 to protect wintering wildlife, with walk-through gates for foot and horse access. No open fires or firewood cutting are allowed on the Portneuf WMA. The Motorized Hunting Rule applies in Unit 72, restricting hunters using motorized vehicles to established roadways legally open to full-sized automobiles during August 30 through December 31. No Access Yes! properties are currently enrolled within the unit itself. Four-wheel-drive vehicles are recommended for many backcountry access roads.

Lower elevations and foothills support sagebrush-steppe and grassland communities, with sagebrush, bitterbrush, serviceberry, and chokecherry as dominant shrubs. Bigtooth maple brush thickets are prominent on north- and east-facing slopes and provide dense thermal and escape cover for deer and elk. Scattered juniper woodlands and patches of aspen occur in the mid-elevation transition zone. Above approximately 6,500 feet, conifer forests of subalpine fir, Douglas-fir, lodgepole pine, and Engelmann spruce take over on north and east aspects, while southern and western exposures remain open or grassy. Roughly 46% of the unit is classified as rangeland and 43% as dryland agriculture, with only about 0.05% classified as forest, underscoring the predominantly open, shrub-steppe and agricultural character of most of the unit.

Mule deer are the primary big-game species, with the unit serving as important fall and winter range; deer move from higher summer ranges into the lower sagebrush and brush-covered foothills as winter approaches. Small but resident elk herds use the unit year-round, with the Chesterfield and Sawmill ranges providing seasonal range. Shiras moose are present, particularly in riparian corridors and drainages near the Blackfoot Reservoir and Portneuf River. Black bear, mountain lion, and gray wolf round out the large predator guild. Wild turkey (Merriam's, reintroduced in 2002) have established huntable populations in the unit's brushy and timbered areas. Upland species include sage-grouse, sharp-tailed grouse, chukar, gray partridge, and pheasant. The Blackfoot Reservoir and associated wetlands support migratory waterfowl, sandhill cranes, and other wetland birds.