Unit 37A 37A (Lemhi)
High-country headwaters unit with goats, sheep, and quality general-season mule deer
Central Idaho — Upper Pahsimeroi, Lost River & Lemhi Ranges (Custer/Lemhi County) · Last reviewed 2026-07-12
Area
346
sq mi
Public land
91%
approx.
Elevation
5,200–11,500
feet
Motorized
moderate
access
Overview
Unit 37A covers the upper Salmon and Pahsimeroi River drainages east of the Salmon River, above the Poison Creek drainage and north and east of the Ellis-May-Howe Highway, in Custer and Lemhi Counties. It is the higher, more forested northern half of the Pahsimeroi country, climbing into the rugged crests of the Lost River and Lemhi ranges. At roughly 90% public — nearly two-thirds Salmon-Challis National Forest and a quarter BLM — it offers general-season mule deer with historically strong success and good buck quality, plus premium controlled tags for bighorn sheep and mountain goat in the alpine. Part of the Lemhi Elk Zone, it holds elk on the timbered slopes as a secondary opportunity.
Terrain
Steep, mountainous headwaters terrain rising from sagebrush benches through conifer and aspen forest into rocky alpine basins and cliff bands along the Lost River and Lemhi crests.
Cover: A rangeland-forest mosaic (~57% range, ~36% forest) — sagebrush and bunchgrass on the lower benches, Douglas-fir, lodgepole, aspen, and subalpine fir on the slopes, and rock and alpine meadow at the highest elevations.
Landmarks: Upper Pahsimeroi River drainage · Lost River Range crest · Lemhi Range crest · Ellis-May-Howe Highway · Poison Creek (excluded, southern boundary)
Access
About 64% Forest Service and 26% BLM, with only ~6% private on the valley-bottom ranches. No designated wilderness. Forest roads climb the drainages into both ranges, though the highest basins require foot access.
Managers: USFS Salmon-Challis NF, BLM Challis/Salmon Field Office, IDL
Access points: Ellis-May-Howe Highway / Pahsimeroi Road · Forest roads up the upper Pahsimeroi drainages · BLM roads onto the lower benches · Trailheads into the Lost River and Lemhi high country
Species notes
Mule Deer
common qualityA general-season mule deer hunt that has historically produced strong success and a good share of four-point-plus bucks using the foothill breaks and high mountain benches.
- →Glass the sage-timber transition and aspen pockets at first and last light
- →Climb into high basins and Douglas-fir stringers for mature bucks
- →Hunt the upper drainages away from roads for older-age-class deer
- →Late-season snow pushes deer down onto lower winter range
Bighorn Sheep
limited trophyA rare, premium controlled bighorn tag for the high rocky crests — few tags, near-total success, and genuine trophy rams.
- →Scout the alpine basins and escarpments of the Lost River and Lemhi crests before season
- →Pattern rams over summer to relocate them at hunt time
- →Be ready for remote, steep, high-elevation stalks
Mountain Goat
limited trophyA once-in-a-lifetime controlled goat tag in the highest cliff country; success is essentially certain when drawn but access is demanding.
- →Focus on the highest crags, cliff bands, and alpine escape terrain
- →Invest scouting days to locate billies before the opener
- →Plan a physically hard pack-in to the high peaks
Rocky Mountain Elk
common opportunityPart of the Lemhi Elk Zone; elk hold in the timbered upper drainages but success is modest, making this a bonus to the strong deer hunt.
- →Hunt north-facing timber and aspen pockets on the mountain flanks at dawn
- →Work the upper drainages and dark benches away from roads
- →Cover ground to locate scattered herds between valley and crest
Black Bear
limited opportunityBlack bears use the forested drainages and berry slopes of the high country — a general opportunity concentrated on the wetter mountain flanks.
- →Glass spring green-up on forested south slopes and avalanche chutes
- →Check aspen draws and berry patches in fall
- →Focus on the higher, timbered basins rather than the arid benches
Pro tips
- →This is a quality general-season deer unit — hunt the high benches and upper drainages, not the roadside sage, for the best bucks
- →If you draw sheep or goat here, treat it as a full backcountry hunt with serious scouting and a hard pack-in
- →The Poison Creek line is the southern boundary versus Unit 37 — confirm which side of the drainage you are on
- →Get above the timber early; the best deer glassing is from high vantage points looking into the basins
- →Snow can close the high forest roads fast in late season — carry recovery gear and watch the forecast
Watch out for
- !Private valley-bottom ranches along the Pahsimeroi — verify boundaries before dropping off the public benches
- !Steep alpine terrain, rockfall, and rapidly changing high-country weather
- !High forest roads drift shut with early snow; four-wheel drive and recovery gear are essential
- !Long approaches to the sheep/goat country — plan food, water, and time accordingly
- !Elk success is modest under the Lemhi Zone — set expectations on the deer hunt instead
Logistics
May and Ellis are the closest settlements, but Challis and Salmon provide the real supplies — fuel, groceries, lodging, and ranger district offices. Dispersed camping is plentiful on Forest and BLM ground up the drainages. Expect rough forest roads and long approaches to the alpine; the highest basins are foot-access only.
Nearest towns: May, Challis, 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 37A boundary, ownership, terrain · IDFG Salmon Region Deer and Elk Hunting Outlook · Salmon-Challis National Forest — Hunting, Fishing and Shooting
FAQ
- How big is Unit 37A in Idaho?
- Unit 37A (37A (Lemhi)) covers about 346 square miles, ranging from roughly 5,200 to 11,500 feet in elevation. Area is computed from the unit boundary polygon.
- How much public land is in Unit 37A?
- Approximately 91% of the unit is public land. Primary managers: USFS Salmon-Challis NF, BLM Challis/Salmon Field Office, IDL. Always verify ownership boundaries on the ground.
- What species does the catalog list for Unit 37A?
- Mule Deer, Bighorn Sheep, Mountain Goat, 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 37A on your map.
Boundary lines, public/private ownership, topo, and offline maps for this unit — in Baseline Maps, free for 14 days.