Unit 37 37 (Lemhi)
High-desert pronghorn stronghold flanked by the Lost River and Lemhi ranges
Central Idaho — Pahsimeroi Valley, Custer/Lemhi County · Last reviewed 2026-07-12
Area
702
sq mi
Public land
87%
approx.
Elevation
5,000–11,000
feet
Motorized
extensive
access
Overview
Unit 37 takes in the Custer and Lemhi County portions of the Salmon and Pahsimeroi River drainages east of the Salmon River, south and west of the Ellis-May-Howe Highway and above US 93 between the Challis bridge and Willow Creek Summit. This is the broad Pahsimeroi Valley — sweeping sagebrush rangeland running between the towering Lost River Range to the west and the Lemhi Range to the east. It is a near-90% public unit (roughly half BLM, one-third Forest Service) and one of the best pronghorn units in the Salmon Region, with very high antelope success. It also holds part of the Lemhi Elk Zone, general-season mule deer, and premium controlled bighorn sheep tags.
Terrain
A wide, arid valley floor of sagebrush flats and alluvial fans climbing steeply into the forested foothills and rocky crests of the Lost River and Lemhi ranges on either flank.
Cover: Dominated by rangeland (~80%) — sagebrush, rabbitbrush, and bunchgrass on the valley and fans — with limited conifer forest (Douglas-fir, aspen) on the higher mountain slopes and irrigated hay ground along the Pahsimeroi River.
Landmarks: Pahsimeroi River valley · Lost River Range (west flank) · Lemhi Range (east flank) · Willow Creek Summit · Ellis-May-Howe Highway
Access
About 49% BLM and 38% Forest Service, with ~10% private concentrated on irrigated valley-bottom ranches along the Pahsimeroi. No designated wilderness. Access is generally good via the Pahsimeroi Road and numerous BLM and Forest roads climbing into both mountain flanks.
Managers: BLM Challis/Salmon Field Office, USFS Salmon-Challis NF, IDL
Access points: US 93 / Salmon River corridor · Pahsimeroi River Road (Ellis-May-Howe Highway) · BLM roads onto the valley benches · Forest roads into the Lost River and Lemhi foothills
Species notes
Pronghorn
common qualityThe signature hunt — the Pahsimeroi's open sagebrush is prime antelope country with excellent controlled-tag success in the 90% range and good buck quality.
- →Glass the wide sagebrush flats and low benches from high vantage points
- →Use terrain folds, draws, and fence lines to close the distance on wary bucks
- →Watch water sources and alfalfa edges early season
- →Judge horns carefully at distance before committing to a long stalk
Mule Deer
common opportunityA solid general-season mule deer hunt with respectable success and a fair share of four-point-plus bucks using the foothill breaks and mountain benches.
- →Glass the brushy foothill transitions where sagebrush meets timber at dawn and dusk
- →Push up into aspen and Douglas-fir pockets for older bucks
- →Hunt the Lost River and Lemhi foothill draws
- →Late-season snow concentrates deer on lower winter range
Bighorn Sheep
limited trophyA very limited, premium controlled bighorn opportunity in the rugged high country — few tags, near-total success, and true trophy rams.
- →Scout the high rocky basins and escarpments of the flanking ranges before season
- →Pattern rams during summer to locate them at hunt time
- →Prepare for steep, remote spot-and-stalk hunting
Rocky Mountain Elk
common opportunityPart of the Lemhi Elk Zone; elk use the timbered mountain flanks but success is modest, so treat it as a secondary opportunity to the deer and pronghorn.
- →Hunt the forested Lost River and Lemhi slopes above the sagebrush
- →Work north-facing timber and aspen pockets at first light
- →Cover ground between the valley and the high benches to locate scattered herds
Black Bear
limited opportunityBlack bears are thin in this arid unit, concentrated in the timbered mountain drainages and riparian stringers — a general opportunity, not a numbers hunt.
- →Glass green-up on forested slopes in spring
- →Check aspen draws and creek bottoms with berry crops in fall
- →Focus effort on the higher, wetter mountain flanks
Pro tips
- →This is a premier pronghorn valley — if you draw the tag, plan for long-range glassing and patient stalks across open sage
- →For mule deer, ignore the flats and hunt the foothill timber-sage edge on both mountain flanks
- →Water is the key resource on the valley floor — pattern early-season antelope and deer around it
- →The unit spans both the Lost River and Lemhi ranges, so pick your flank and learn its road system rather than trying to cover both
- →Respect the irrigated ranch inholdings along the Pahsimeroi River — much of the bottomland is private
Watch out for
- !Private irrigated ranches line the Pahsimeroi River bottom — verify boundaries before hunting the valley floor
- !Very limited water on the sagebrush flats; dehydration and vehicle range are real concerns
- !Afternoon heat early season; hunt dawn and dusk
- !High mountain roads can drift shut with early snow
- !Elk success is modest under the Lemhi Zone — set expectations accordingly
Logistics
Challis (west) and Salmon (north) are the main supply points for fuel, food, and lodging; the tiny hamlets of May and Ellis anchor the valley itself. Dispersed camping is easy on BLM and Forest ground; the valley's road network makes truck-camp hunting practical. Water is scarce on the flats — haul your own.
Nearest towns: Challis, May, Ellis, Salmon
Seasons & regulations
This page carries no season dates or regulations. Get current rules from the official Idaho sources:
Research sources: IDFG Hunt Planner — Unit 37 boundary, ownership, terrain · IDFG Salmon Region Deer and Elk Hunting Outlook · Salmon-Challis National Forest — Hunting, Fishing and Shooting
FAQ
- How big is Unit 37 in Idaho?
- Unit 37 (37 (Lemhi)) covers about 702 square miles, ranging from roughly 5,000 to 11,000 feet in elevation. Area is computed from the unit boundary polygon.
- How much public land is in Unit 37?
- Approximately 87% of the unit is public land. Primary managers: BLM Challis/Salmon Field Office, USFS Salmon-Challis NF, IDL. Always verify ownership boundaries on the ground.
- What species does the catalog list for Unit 37?
- Pronghorn, Mule Deer, Bighorn Sheep, Rocky Mountain Elk, Black Bear. For seasons, tags, and regulations, use the official Idaho agency resources linked on this page — this page carries no regulatory information.
Put Unit 37 on your map.
Boundary lines, public/private ownership, topo, and offline maps for this unit — in Baseline Maps, free for 14 days.