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
High Desert State Prison (California) High Desert State Prison (California) High Desert State Prison (HDSP) is a high-security state prison that houses level IV inmates located in Susanville, Lassen County, California. Opened in 1995, it has a capacity of 2,324 persons; in May 2017 it held 3,788 inmates. Also located in Susanville is the state California Correctional Center, a minimum-security prison. A third prison facility, the Federal Correctional Institution, Herlong, is also located within Lassen County, California. Half the adult population of Susanville works at these prisons. The prisons and their effects on the community, including as a source of much needed jobs, were explored