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
Desert Uniforms, Patches, and Insignia of the US Armed Forces that, "In preparation for the book, they accumulated more than 1,000 government and theater-made desert patches and over 300 uniforms. A large number are in it. These came from numerous veterans and collectors...Born said, “writing the book was about two things for us – recognizing the service and sacrifice of the men and women of the armed forces who wore the desert uniform as well as advancing this area of military collecting. Whenever a reference like this is published, there is an increased interest among collectors.” Desert Uniforms, Patches, and Insignia of the US Armed Forces Desert Uniforms, Patches, and