Unit 37A, Idaho

The unit spans a dramatic elevation gradient from roughly 4,400 feet along the Salmon River near Elk Bend to peaks and ridges in the Lemhi Range exceeding 11,000 feet. The Pahsimeroi Valley floor (the eastern portion of the unit) is comparatively flat, ranging from about 5,000 to 6,250 feet. Foothills above the Salmon River and Pahsimeroi Valley feature steep breaks and rock outcroppings. Upper slopes transition to rugged, predominantly roadless high country with ridgelines and cirques above treeline at roughly 9,500 feet. The unit is approximately 56.6% rangeland and 36.3% forested terrain, with irrigated agricultural sections (about 7%) in the valley floors.

The primary land manager is the Salmon-Challis National Forest (Challis-Yankee Fork Ranger District; office at 208-879-4100, Challis, ID). US-93 forms the western and southern unit boundary, connecting Challis (to the south) with Salmon (to the north); the Salmon River parallels this highway. The Ellis-May-Howe Highway (connecting the communities of Ellis, May, and Howe) forms the eastern and northern boundary and provides access to the Pahsimeroi Valley from Idaho Highway 28. Forest Service roads and BLM roads provide vehicle access into foothills and mid-elevation drainages, though many roads crossing private valley-floor land require careful route planning; access from the north via Highway 28 avoids private-land conflicts on some entry corridors. The Idaho Motorized Hunting Rule applies unit-wide August 30 through December 31, restricting motorized vehicle use to established roadways legally open to full-sized automobiles — no off-road motorized travel is permitted for big game hunting. The high country above approximately 9,000 feet is predominantly roadless and requires foot or horseback travel. There are no federally designated wilderness areas within Unit 37A itself, though the Frank Church–River of No Return Wilderness lies in adjacent units to the west. USFS campgrounds are located on Morse Creek and Big Creek inside the unit. BLM maintains additional dispersed camping and road access in the lower foothills; the BLM Challis Travel Map details open routes. Four-wheel-drive is advised on many canyon and mountain roads. No Access Yes! properties are currently listed for this unit.

Lower foothills and canyon breaks are dominated by sagebrush-steppe and native bunchgrass interspersed with mountain mahogany, juniper, and aspen groves in drainages. Mid-elevation slopes and draws support mixed stands of Douglas-fir, aspen, and mountain mahogany transitioning to denser spruce, fir, and lodgepole pine forests in the 6,500–9,000 foot zone. Above 9,500 feet vegetation grades into alpine shrubs, forbs, grasses, and exposed rock. Riparian corridors along the Salmon River and Pahsimeroi River support willows and cottonwoods. The Pahsimeroi Valley contains irrigated hay fields and pastures that attract elk and deer in fall.

Mule deer are the most abundant big game in the unit, occupying sagebrush foothills in summer and fall before moving to lower valley terraces in winter. Mule deer numbers east of the Salmon River (which includes Unit 37A) are stable to slightly declining per IDFG regional outlook data. Elk populations have expanded substantially in the Pahsimeroi Valley over recent decades; herds now winter on valley irrigated fields. Elk in the Lemhi Zone are assessed as at or above management objectives. Bull elk rut activity typically begins in early September and runs through early October. Pronghorn antelope are present in the open sagebrush-steppe and valley-floor areas. Black bear inhabit mid-elevation forest and brushy drainages. Mountain lion are present. Gray wolf populations are established in the Salmon-Challis National Forest ecosystem. Moose, Rocky Mountain bighorn sheep, and mountain goat occur in the unit in small numbers and are subject to controlled-hunt only management. Sage-grouse, chukar, and forest grouse (blue and ruffed) use appropriate habitat types.