Unit 48, Idaho

The unit spans roughly 610 square miles and ranges in elevation from approximately 4,900 feet in the valley bottoms to 10,300 feet along the ridgelines, with Hyndman Peak (12,012 ft) on the unit's eastern fringe in the Pioneer Mountains. Lower elevations consist of agricultural valleys and foothills with a mix of private, BLM, and state land; mid-elevation terrain is forested and rolling; upper terrain above 9,000 feet is open with rock slides, talus fields, grassy alpine basins, and brushy draws. The Big Wood River is the primary drainage running north to south through the unit, with Trail Creek draining the eastern edge near Ketchum.

The unit is accessed primarily via U.S. Highway 75 (the Sawtooth Scenic Byway), which runs north-south through Ketchum and forms part of the eastern boundary. U.S. Highway 20 forms the southern boundary. Interior access routes include Dollarhide Road (following the Warm Springs Creek drainage southwest from Ketchum over Dollarhide Summit into the Smoky Mountains), Trail Creek Road (connecting Sun Valley over Trail Creek Summit through the Pioneer Mountains to Mackay), and North Fork Road off Highway 75 north of Ketchum toward the Sawtooth NRA. The Sawtooth National Forest (Ketchum Ranger District) administers the majority of public land (USFS 69.4% + BLM 11.8% + State 2.1% = 83.3% total public); BLM manages additional parcels in the lower foothills. There are no federally designated Wilderness areas within GMU 48 boundaries. Developed campgrounds within or adjacent to the unit include Boundary Campground north of Ketchum, Copper Creek/Garfield, East Fork Baker Creek, and Federal Gulch. The IDFG Access Yes! program provides access across enrolled private parcels. The Forest Service publishes a Motor Vehicle Use Map (MVUM) governing road and trail access. Seasonal road closures apply to many forest roads due to snow, typically from late autumn through late spring.

Vegetation is strongly aspect-driven. North- and east-facing slopes above 6,500 feet support Douglas fir, Engelmann spruce, subalpine fir, and lodgepole pine, with an understory of huckleberry, snowberry, white spirea, mallow ninebark, and Oregon grape. Aspen stands appear at mid-elevation riparian corridors and on transition slopes. South- and west-facing slopes carry open grassland and big sagebrush steppe from valley floor through mid-elevation. Land cover in the unit is roughly 52% rangeland, 38% forest, 4% riparian, and 5% agricultural. The upper alpine zone is dominated by rock, scree, and open grassy basins.

Elk are the premier big-game species; the unit lies within the Smoky-Bennett Elk Zone (units 43, 44, 45, 48, and 52), which supports an estimated herd of approximately 4,871 animals (2015 zone-wide winter survey), with the herd at or above management objectives for both cows and bulls. Bull-to-cow ratios were recorded at 36 bulls per 100 cows with a calf/cow index of 43 calves per 100 cows. Mule deer are widely distributed across the sagebrush and forested foothills and constitute the most heavily hunted big game species in the unit. White-tailed deer are present in limited numbers in riparian bottoms. Moose occur in small numbers in riparian and willow habitats, with a controlled hunt quota of 4 tags. Black bear inhabit the forested mid and upper elevations. Mountain lion are present year-round. Gray wolf packs are established in the region. Upland birds include blue/ruffed grouse, sage-grouse, chukar, and pheasant in appropriate habitat. Elk and deer undertake seasonal migrations between high-elevation summer range and lower-elevation winter range, with animals generally moving down from alpine terrain into forested mid-slopes and sagebrush foothills from September onward as snow accumulates.