To many visitors, the bighorn sheep is the epitome of Cabeza Prieta National Wildlife Refuge's desert wilderness. Bighorns are a true sheep distantly related to domestic sheep.
Biologists recognize four races of desert bighorn.
The desert bighorn has become well adapted to living in the desert heat and cold and, unlike most mammals, their body temperature can safely fluctuate several degrees. During the heat of the day, bighorn often rest in the shade of trees and caves. Cabeza Prieta NWR's bighorn and those further south in Mexico are typically found in small scattered bands adapted to a desert mountain environment with little or no permanent water. Some of the bighorn may go without visiting one of the refuge's water developments for weeks or months, sustaining their body moisture from food and from rainwater collected in temporary rock pools. They may have the ability to lose up to 30 percent of their body weight and still survive.