Unit 16, Idaho

Terrain ranges from roughly 1,500 to 6,000 feet elevation. The eastern three-quarters of the unit is mountainous — steep, rocky ridges and deep river canyons carved by the South Fork of the Clearwater and the Selway River. The Selway-Bitterroot Wilderness portion in the northeast corner is the most rugged, featuring open rocky slopes, avalanche chutes, small mountain lakes, and scattered subalpine timber. The western fringe transitions to broader flats, rolling foothills, and agricultural benchlands near the Kooskia/Harpster area. Most of the Nez Perce National Forest portion is accessible by forest roads, but steep drainages and the wilderness area remain roadless. The unit covers approximately 248,879 acres.

Primary highway access is via State Highway 14, which follows the South Fork of the Clearwater River from Grangeville eastward to Elk City, bisecting the southern portion of the unit. Highway 13 connects Grangeville to Kooskia and provides northwest entry. Highway 12 along the Clearwater River corridor runs north of the unit and provides access to the Selway River Road (Forest Road 223), which enters the wilderness area from the north near Lowell and Wilderness Gateway Campground. The Magruder Corridor Road (Forest Road 468) — a rough, 101-mile, single-lane route — provides the primary motorized access along the southern edge; high-clearance vehicles are required. Most of the Nez Perce National Forest interior is accessible via a network of forest roads. The Selway-Bitterroot Wilderness (12,119 acres, 4.87% of the unit) prohibits all motorized and wheeled vehicles; access there is foot or stock only, with a 20-person/20-head-of-stock group size limit and 14-day camping limit. Land ownership: USFS 78.3%, private 18.7%, State of Idaho 1.5%, Indian Reservation/BIA 0.9%, BLM/other 0.5%.

Vegetation is highly diverse by elevation. The high Selway-Bitterroot Wilderness terrain supports subalpine fir, Engelmann spruce, and whitebark pine with open rocky basins, brushy avalanche chutes, and meadows. Mid-elevation mountains are heavily forested with mixed conifers — ponderosa pine, Douglas-fir, grand fir, western larch, and lodgepole pine. South-facing slopes throughout the unit are characteristically open, with grass, shrubs, and scattered timber creating important thermal and feeding habitat. Lower elevations along the South Fork of the Clearwater River corridor support dense riparian forests. The western portion near Kooskia grades into dry farm fields, pastures, and benches with scattered pines, poplars, and cottonwoods in draws — habitat that supports the unit's whitetail deer population. Land cover: 72% forest, 17% dryland agriculture, 11% rangeland.

Elk are the primary big game species; Unit 16 is part of the Elk City Zone (Units 14–16). As of the 2025 IDFG outlook, elk numbers in Units 15 and 16 remain below long-term averages, though recent improvements in calf recruitment offer a more optimistic trajectory; Unit 14 functions as the zone's stronghold. White-tailed deer are common in the western half of the unit, particularly in the agricultural fringe and lower-elevation draws near Kooskia and Harpster. Mule deer inhabit the drier, open ridges and higher-elevation terrain. Black bears are present throughout. Gray wolves have been documented and are huntable. Mountain lions occupy the unit. Moose are a huntable species per IDFG. Upland birds include forest grouse, wild turkey, pheasant, sage-grouse, sharp-tailed grouse, gray partridge, chukar, quail, dove, and crow. Waterfowl use the Clearwater and Selway river corridors.