Nellis Wash Wilderness is a 16,423-acre protected desert landscape in southern Nevada on the eastern side of the Newberry Mountains, extending toward Lake Mohave and adjoining Spirit Mountain Wilderness at its southern edge. Managed by the National Park Service within Lake Mead National Recreation Area and also lying in Avi Kwa Ame National Monument, it preserves a stark Mojave Desert environment of rugged mountain slopes and dry washes. Extreme summer heat, no nearby fresh water, creosote bush, catclaw acacia, black-tailed jackrabbits, horned lizards, kangaroo rats, and traces of earlier mining activity all characterize this largely undeveloped wilderness, designated in 2002.