Unit 43B, Arizona

Hot low desert terrain ranging from roughly 100–200 feet elevation near the Colorado River to approximately 3,000 feet at the higher desert peaks. Topography is very rocky with large desert washes separating sharply rising, rugged mountain ranges. Broad, gently sloping bajada foothills transition to needlepoint peaks and deeply cut canyons. Most areas require foot access; vehicle roads provide approach routes only and four-wheel drive is essential.

Primary highway access via U.S. Highway 95 (the unit's western spine, running north-south through Quartzsite, and Yuma) and Interstate 8 (southern boundary). Internal access roads include Castle Dome Road (northeast access toward the Kofa NWR boundary), Stone Cabin–King Valley Road (northern access road, also called King Road), Red Cloud Mine Road (Trigo Mountains approach), and Cibola Lake Road (northwest, reaches the Colorado River corridor). Colorado River boat launches at Hidden Shores, Martinez Lake, and Meer's Point provide water access. Most interior roads are unmarked BLM two-tracks; four-wheel drive required. The majority of the unit overlaps U.S. Army Yuma Proving Ground (YPG): hunters drawn for big game who plan to hunt YPG must obtain a Hunting Access Permit via iSportsman (yuma.isportsman.net) before entry, requiring online registration, a Range Safety Briefing video, and a background check that takes 2–3 business days per the 2026-27 AZGFD regulations; all firearms and bows must be registered at the visitor center or through iSportsman before entering YPG. Due to military activities, some YPG areas close on short notice; updates are posted at yuma.isportsman.net. The BLM Yuma Field Office manages the Trigo Mountain Wilderness. Imperial National Wildlife Refuge and Mittry Lake Wildlife Area (both within unit boundaries) have posted day-use and closure regulations — no camping in posted day-use-only areas at Mittry Lake. Kofa NWR abuts the northeast unit boundary but is not within 43B. Unit boundary per AZGFD: from the south end of Cibola Lake, south along the AZ-CA state line to I-8, southeast on I-8 to US 95, northeast on US 95 to Castle Dome Road, northeast on Castle Dome Road to the Kofa NWR boundary, north along the refuge boundary to Stone Cabin-King Valley Road (King Road), west along King Road to US 95, north on US 95 to Cibola Lake Road, west and south on Cibola Lake Road back to the south end of Cibola Lake; excluding sovereign tribal lands of the Quechan Tribe.

Classic Sonoran/Yuma Desert scrub dominated by creosote bush, saguaro cactus, palo verde, cholla, ironwood, and brittlebush on upland slopes and bajadas. Dense mesquite bosque, tamarisk, and riparian willow-cottonwood communities line the Colorado River corridor and major desert washes. Rocky canyon walls and talus slopes in the mountain ranges provide desert bighorn habitat. Mittry Lake and the Imperial National Wildlife Refuge shoreline support emergent marsh and open-water habitat attracting waterfowl and dove. No ponderosa pine, chaparral, or pinyon-juniper — this unit sits below 3,000 feet in the hottest, driest region of Arizona.

Desert bighorn sheep occupy rocky canyon and mountain range habitat throughout the unit, with one of the most stable populations in the state per AZGFD; primary habitat is on YPG. Mule deer are present at low density in desert washes, broad flats, and riparian corridors; the best concentrations occur north of US 95/east of Kofa NWR boundary and in the Cibola Lake area. Javelina range throughout desert scrub and wash systems. Mountain lion occur sparsely, occasionally moving between Kofa NWR and the Chocolate Mountains on YPG. Dove (including white-winged and mourning) concentrate in the agricultural Gila Valley. Gambel's quail populations fluctuate with precipitation, with the highest densities on Imperial NWR. Waterfowl and wading birds use Martinez Lake and the Colorado River backwaters extensively. No elk, pronghorn, or turkey occupy this unit — no hunts are listed for these species in 43B in the 2026-27 AZGFD regulations.