Desert bighorn sheep establish two desert areas in southwestern Arizona to help preserve the desert bighorn sheep: Cabeza Prieta National Wildlife Refuge and the Kofa National Wildlife Refuge. In 1941, the San Andres National Wildlife Refuge in New Mexico was added. Desert bighorn sheep populations have trended upward since the 1960s when their population was estimated at 6,700-8,100. The upward trend was caused by conservation measures, including habitat preservation. In 1980, desert bighorn sheep populations were estimated at 8,415-9,040. A state-by-state survey was conducted a few years later and estimated the overall US desert bighorn sheep population at 15,980. The 1993 estimate of
Painted Desert Community Complex Historic District is the Painted Desert Visitor Center, designed as a severely modernist structure that includes administrative offices., a visitor center, an auditorium, a clinic and staff apartments. Other structures include a community center, school and a Fred Harvey Company concession building. Neutra and Alexander paid particular attention to the division of the complex into public and private areas, using low walls to divide the Park Service service area from the central zone, and setting the inward-facing residential areas at a distance. Pedestrian circulation paths are used as defining organizing elements. The original landscape design used non-native plants that required regular watering.