Pepperweed wildflower blooms amoung the sand dunes in The Cabeza Prieta National Wildlife Refuge is located in the Sonoran Desert in southwestern Arizona in the United States. The refuge, established in 1939 to protect Desert Bighorn Sheep, is located along 56 miles (90 km) of the U.S.-Mexico border, and covers 860,010 acres (3,480 km²) — larger than the land area of the state of Rhode Island.
Spanish for "dark head," the refuge's name comes from the Cabeza Prieta Mountains in the refuge's northwest part. Author Edward Abbey, a frequent visitor, described the Cabeza Prieta as "the best desert wilderness left in the USA.