The wilderness area encompasses the rugged granitic Chemehuevi Mountains. The mountain range is horseshoe-shaped, with the open end facing eastward toward the Colorado River. Contained within the arms of the horseshoe is a large central valley with low rolling hills covered by dense stand of cholla and other cacti, ocotillo, and an occasional agave. Viewed from the west, the striking light, almost white, granite peaks contrast sharply with the rich green creosote and cactus-covered bajada. A few miles from the Colorado River, the mountains change dramatically from light-colored granite to dark red and gray volcanic spires and mesas. Broad, sandy, tree-lined Red Rock and Trampas Washes cross the wilderness from west to east. A number of springs and seeps a found in the area. The flora and fauna in the area are rich in species diversity due to its position between the Sonoran and Mohave Desert ecosystems and due to the infusion of river species and species principally found in eastern Arizona. Wildlife includes bighorn sheep, wild burros, desert mule deer, mountain lions, coyote, black-tailed jackrabbits, ground squirrels, kangaroo rats, roadrunners, quail, rattlesnakes, and several species of lizards. The extreme southwestern portion of the wilderness provides critical habitat for the threatened desert tortoise.