The largest plant category in the national monument is collectively known as desert scrub and includes Sonoran Cresosote Scrub and Sonoran Mixed Woody and Succulent Scrub vegetation communities. Desert scrub occupies more than and consists of creosote bush (Larrea tridentata), burrobrush (Ambrosia dumosa), cacti, and other stem succulents. Desert scrub is found on the alluvial fans and intermountain bajadas, growing on coarse, well-drained soils. Wildlife of the desert scrub plant community includes the federally protected Peninsular Ranges bighorn sheep (Ovis canadensis nelsoni) and the desert tortoise (Xerobates agassizii syn. Gopherus agassizii).