GMU 37A Unit 37A — Tucson
A physically easy desert bighorn unit in the ironwood-and-saguaro flats of the Silver Bells
Sonoran desert northwest of Tucson — Ironwood Forest & Silver Bell Mountains · Last reviewed 2026-07-12
Area
1,679
sq mi
Public land
—
approx.
Elevation
1,800–4,300
feet
Motorized
moderate
access
Overview
Unit 37A spreads across the low Sonoran desert northwest of Tucson, mostly flat creosote-and-ironwood bajada with a handful of small, rugged desert ranges — the Silver Bell, Sawtooth, Roskruge, and Waterman mountains — rising abruptly out of the lowlands. Much of the public ground falls within BLM's Ironwood Forest National Monument. The unit's marquee tag is the desert bighorn sheep of the Silver Bell/Sawtooth herd, a quality but very limited draw that offers a physically easy hunt by sheep standards. Deer are sparse: desert mule deer scatter through the ranges and washes with a few Coues in the higher rock, and harvest numbers are low.
Terrain
Expansive flat Sonoran bajada punctuated by isolated, rocky desert mountain ranges; hunting is not physically demanding but heat is the real hazard.
Cover: Sonoran desert scrub — saguaro, ironwood, paloverde, creosote, cholla — with sparse desert grassland; rugged rock and thin brush on the peaks.
Landmarks: Silver Bell Mountains · Ragged Top · Sawtooth Mountains · Waterman Mountains · Roskruge Mountains · Ironwood Forest National Monument
Access
BLM and state trust lands are public and open to hunting; a State Land recreation permit is required for state trust sections. Much of the eastern side is private and closed. The Tohono O'odham Nation borders the unit and is closed to general AZGFD hunting. Access is primarily via desert dirt roads through Ironwood Forest NM off Silverbell Road and I-10 frontage; a high-clearance vehicle is useful.
Managers: BLM (Ironwood Forest National Monument), AZ State Trust, Private, Tribal (Tohono O'odham — closed)
Access points: Silverbell Road · Interstate 10 (Marana/Red Rock exits) · Avra Valley Road · Ironwood Forest NM dirt roads
Species notes
Bighorn Sheep
limited trophyDesert bighorn of the Silver Bell/Sawtooth ranges are the headline species — a very limited draw (a handful of tags) with a strong success rate and a relatively easy hunt by sheep standards; recent seasons added hunts on the north end.
- →Glass the rocky peaks and rims of the Silver Bell and Sawtooth ranges at first light
- →Scout water sources and catchments the desert sheep depend on
- →Set up on high vantage points and let the optics do the walking
Mule Deer
limited opportunityDesert mule deer are thinly scattered through the ranges and washes; densities are low and harvest is modest, so it is a cover-ground, low-expectation deer hunt.
- →Glass bajada washes and range edges at dawn and dusk
- →Key on ironwood and paloverde draws near water
- →Be mobile — deer are patchy across the open desert
Whitetail Deer
transient opportunityA few Coues whitetail hold in the higher, rougher rock of the desert ranges but this is a fringe, incidental opportunity rather than typical 37A deer hunting.
- →Glass the steepest upper rock of the Silver Bell and Waterman ranges
- →Focus on the highest brush and rimrock
- →Expect very low numbers — treat any Coues as a bonus
Pro tips
- →For sheep, pre-scout water catchments in the Silver Bells — desert bighorn orbit reliable water
- →Bring more water than you think you need; heat, not terrain, is the challenge here
- →Use the flat approach to your advantage: glass long from high points rather than grinding miles
- →Stay on the public BLM/state-trust checkerboard — the eastern private ground is closed
- →A high-clearance vehicle opens more of the Ironwood Forest dirt-road network
Watch out for
- !Tohono O'odham Nation borders the unit and is closed to general hunting
- !Extensive private land on the east side is posted and closed
- !State trust sections require a State Land recreation permit
- !Extreme desert heat and scarce water — a genuine safety concern
- !Remote dirt roads with poor cell coverage — carry recovery gear and tell someone your plan
Logistics
Marana, Casa Grande, and Tucson along I-10 provide full services, fuel, and lodging within easy reach. The unit is close to the metro and easy to reach, but it is dry, open desert — carry abundant water and plan for heat. Cell coverage fades on the interior dirt roads of the monument.
Nearest towns: Marana, Red Rock, Eloy, Casa Grande, Tucson
Seasons & regulations
This page carries no season dates or regulations. Get current rules from the official Arizona sources:
Research sources: Arizona Unit 37A Unit Profile — GOHUNT · Arizona Desert Bighorn Sheep Hunts — Dieringer Outfitters · Arizona Bighorn Sheep Hunting 2026 — Huntin' Fool
FAQ
- How big is GMU 37A in Arizona?
- GMU 37A (Unit 37A — Tucson) covers about 1,679 square miles, ranging from roughly 1,800 to 4,300 feet in elevation. Area is computed from the unit boundary polygon.
- What species does the catalog list for GMU 37A?
- Bighorn Sheep, Mule Deer, Whitetail Deer. For seasons, tags, and regulations, use the official Arizona agency resources linked on this page — this page carries no regulatory information.
Put GMU 37A on your map.
Boundary lines, public/private ownership, topo, and offline maps for this unit — in Baseline Maps, free for 14 days.