Unit 21A, Idaho

Unit 21A spans roughly 249 square miles with elevations ranging from approximately 3,800 feet in the lower Salmon River corridor to 10,000 feet along the high ridges near the Montana border at Lost Trail Pass. The landscape transitions from open sagebrush foothills and river-bottom hay/alfalfa fields (4,000–6,000 ft) to timbered mid-mountain terrain (6,000–9,000 ft) and rocky subalpine ridges and bowls above 9,000 ft. Stream gradients are steep throughout much of the North Fork drainage.

Primary access is via US Highway 93, which runs through the Salmon River canyon and through the town of North Fork. Secondary road access includes Gibbonsville Road (northeastern drainages), Lick Creek Road, Dry Sheep Creek Road, and Carmen Creek Road. Forest roads and ATV trails penetrate the interior; four-wheel-drive and high-clearance vehicles are recommended for most backcountry routes. The Salmon-Challis National Forest (North Fork Ranger District, 11 Casey Rd, North Fork, ID 83466; 208-865-2700) manages 73.78% of the unit. BLM holds 14.14%. There are no federally designated wilderness areas within GMU 21A itself. Some motorized routes have seasonal closures due to snow; verify current conditions with the North Fork Ranger District.

Lower river corridors support cottonwoods, willows, sagebrush-steppe, and irrigated hay/alfalfa fields (land cover: ~9% irrigated, ~20% rangeland, ~71% forest per IDFG). Foothills carry bunchgrasses, wild grasses, shrubby brush, and scattered ponderosa pine. At mid-elevations the forest shifts to Douglas-fir, lodgepole pine, and aspen stands. Upper slopes and north-facing drainages support Engelmann spruce and subalpine fir, with timberline occurring around 9,000 feet.

The unit supports elk, mule deer, white-tailed deer (river bottoms and private fields), pronghorn (lower sagebrush zones), black bear, mountain lion, gray wolf, and moose. Bighorn sheep and mountain goat are listed by IDFG as present. Elk use higher timbered slopes and alpine meadows in summer and early fall, migrating to lower river-bottom and foothills terrain as winter approaches; some elk congregate near private agricultural fields in late season. Mule deer follow similar elevation-driven seasonal movement patterns. Whitetail are concentrated near private land along the Salmon River corridor. The North Fork and main Salmon River support wild salmon, steelhead, cutthroat trout, and rainbow trout.