Home to the picturesque and rugged Eldorado Mountains, this wilderness unit is a maze of peaks and side canyons with vertical cliffs extending to the edge of the Colorado River. Much of the terrain was formed by volcanism. This scenic area contains some remnants of past mining. Water is scarce and the summer temperatures can reach 120 degrees Fahrenheit. Archeological resources include petroglyphs, lithic scatters and an intaglio. Mountain lions, bighorn sheep, coyotes, and jackrabbits are among the many creatures that inhabit the area. Watch closely for the side-blotched lizard, rattlesnake, or desert tortoise caught sunning itself in the afternoon sun.