How big is GMU 45C in Arizona?

GMU 45C (Unit 45C — Yuma) covers about 302 square miles, ranging from roughly 700 to 3,788 feet in elevation. Area is computed from the unit boundary polygon.

What species does the catalog list for GMU 45C?

Bighorn Sheep, Mule Deer. For seasons, tags, and regulations, use the official Arizona agency resources linked on this page — this page carries no regulatory information.

GMU 45C Unit 45C — Yuma

A desert bighorn stronghold locked inside the Kofa Refuge, with a hard-earned desert mule deer hunt below the Castle Domes.

Southwestern desert — Kofa National Wildlife Refuge · Last reviewed 2026-07-13

Area

302

sq mi

Public land

100%

approx.

Elevation

700–3,788

feet

Motorized

limited

access

Overview

Unit 45C lies entirely within the Kofa National Wildlife Refuge northeast of Yuma, some of the most storied desert bighorn country in the Southwest. The dark volcanic Castle Dome Mountains rise abruptly from broad bajadas and washes, holding water in tinajas that concentrate sheep and, in wetter years, a scattered population of desert mule deer. This is a federal refuge, not multiple-use land: travel is restricted to designated roads, tags are scarce and coveted, and the reward for drawing one is a wild, roadless experience.

Terrain

Rugged desert mountain island (Castle Dome and Kofa ranges) surrounded by expansive alluvial flats and deep braided washes draining toward the Colorado River lowlands.

Cover: Sonoran/Lower Colorado desert scrub — creosote, ocotillo, palo verde, ironwood and saguaro on the bajadas; sparse cover and shade in the rocky canyons and around tinaja waterholes.

Landmarks: Castle Dome Peak · Castle Dome Mountains · King Valley · Stone Cabin–King Valley Road · Kofa NWR tinajas

Access

The entire unit is Kofa NWR managed by the U.S. Fish & Wildlife Service. Vehicle travel is limited to designated open roads only — cross-country driving is prohibited, including in washes and for game retrieval. The Stone Cabin–King Valley (King) Road forms the northern and eastern boundary. Access the southern end from Castle Dome Road off US-95 near milepost 55.

Managers: USFWS Kofa National Wildlife Refuge, BLM (fringe)

Access points: Castle Dome Road off US-95 (MP 55) · Stone Cabin–King Valley Road · King Valley Road corridor

Species notes

Bighorn Sheep

common trophy

Kofa is one of Arizona's premier desert bighorn factories; the Castle Dome and Kofa ranges hold mature rams and once-in-a-lifetime tags draw at extremely long odds. Success on drawn hunts is effectively total.

→Glass volcanic cliff faces and steep canyon rims at first and last light from high vantage points
→Focus on tinajas and reliable water sources — rams stay tied to water in the heat
→Pack quality optics and plan multi-day spike camps; the country is roadless and vertical
→Study lamb/ewe groups early to pattern rams before the hunt

Mule Deer

limited opportunity

Desert mule deer are thinly scattered across the bajadas and washes around the Castle Domes. Densities are low and success is modest (roughly a quarter of hunters), making this a patient, low-pressure opportunity hunt rather than a trophy destination.

→Glass major washes and palo verde/ironwood bottoms at dawn where deer feed and bed
→Hunt near the mountain-desert interface and washes that hold browse after rains
→Cover ground on foot from designated roads — deer are sparse and mobile
→Time hunts to cooler weather and any water sources holding after monsoon

Pro tips

→Scout waterholes and tinajas ahead of time — in this desert, water is the single best predictor of animal location
→Respect the road closures rigorously; USFWS enforces no cross-country travel, even to pack out an animal
→Bring more water, shade and heat mitigation than seems reasonable — this is unforgiving low desert
→Glass long and often from elevation; sheep blend into the dark volcanic rock
→Plan for full self-sufficiency — no cell service, sparse traffic, long distances to help

Watch out for

!Kofa NWR travel restrictions — designated roads only, no cross-country driving or wash travel
!Extreme heat and dehydration; summer/early-fall temperatures reach dangerous levels
!No reliable water — carry your own; tinajas are wildlife resources, not dependable resupply
!Remote and roadless interior with no cell coverage; self-rescue capability required
!Rugged, steep, loose volcanic terrain in the sheep ranges

Logistics

Yuma (via US-95) is the primary staging town for fuel, water, ice and supplies; Quartzsite anchors the north. Carry far more water than you think you need, a high-clearance 4WD, recovery gear and full self-rescue capability — there are no services and limited traffic inside the refuge. Cell coverage is unreliable to nonexistent.

Nearest towns: Yuma, Quartzsite, Wellton

Nearby units

GMU 45B · Unit 45B — Yuma GMU 45A · Unit 45A — Yuma GMU 43B · Unit 43B — Yuma GMU 41 · Unit 41 — Yuma, Mesa

Seasons & regulations

This page carries no season dates or regulations. Get current rules from the official Arizona sources:

Research sources: AZGFD Where to Hunt — Unit locator · HuntScore — Arizona GMU 45C · Hunt Now Arizona — Unit 45C · Kofa NWR — USFWS

FAQ

How big is GMU 45C in Arizona?: GMU 45C (Unit 45C — Yuma) covers about 302 square miles, ranging from roughly 700 to 3,788 feet in elevation. Area is computed from the unit boundary polygon.
How much public land is in GMU 45C?: Approximately 100% of the unit is public land. Primary managers: USFWS Kofa National Wildlife Refuge, BLM (fringe). Always verify ownership boundaries on the ground.
What species does the catalog list for GMU 45C?: Bighorn Sheep, Mule Deer. For seasons, tags, and regulations, use the official Arizona agency resources linked on this page — this page carries no regulatory information.

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