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
The Oregon Desert bobcat food, and high desert ghost towns. From its first release in 1964, "The Oregon Desert" has received excellent reviews from numerous sources. On 7 October 1964, the Eugene "Register-Guard" newspaper said: To commemorate Oregon's sesquicentennial in 2009, the Oregon State Library recommended 150 Oregon-related books including "The Oregon Desert". According to the Oregon State Library, this book is "a classic account of the places, events, animals and people in the High Desert region." In highlighting "The Oregon Desert" in its section on Oregon authors and books, the Oregon Blue Book quoted from Google Books as follows: "The Oregon Desert"