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 Inn as the Stone Tree House due to much local petrified wood used in its architectural elements. After post-war design revisions by architect Mary Jane Colter, it was operated by the Fred Harvey Company as a Harvey House from 1947 to 1963, when it closed. Demolition was proposed in the mid-1970s, but after public protests the building was reopened for limited use in 1976. It was declared a National Historic Landmark in 1987. The main lodge building of the Painted Desert Inn was extensively rehabilitated and restored, reopening as a museum and bookstore in 2006. Overnight accommodations and food service are