The Sweeney Granite Mountains Desert Research Center is located in the rugged Granite Mountains of the East Mojave Desert. High plateaus and ridges dominated by piñon-juniper woodland and sagebrush descend precipitously to the east in highly fractured granitic canyons. Massive pinnacles and broken, rocky terrain eventually give way to densely vegetated bajadas and washes, supporting creosote bush scrub, a unique community of enriched mixed woody and succulent scrub, and other habitat types. Springs and seeps are common. Variation in habitat, hydrology, and elevation supports widely diverse plant and animal life, including more than 460 species of vascular plants, two amphibians, thirty-four reptiles, 138 birds, and 42 mammals. The reserve also protects a dense concentration of archeological sites left by Chemehuevi and other Native American tribes. This NRS reserve lies within the recently established Mojave National Preserve. Operating as a satellite site is the Sacramento Mountains Reserve, which lies on the steep slopes and flat bajadas of the Sacramento Mountains in the East Mojave Desert. This satellite site supports several Sonoran Desert plant species, including Bigelow teddy bear cholla, along with a small, disjunct colony of ocotillo, one of this species’s northernmost occurrences.