The San Bernardino National Wildlife Refuge is located on the U.S., Mexican border in Cochise County, Arizona, 17 miles east of the City of Douglas. Situated at 3,720 to 3,920 feet elevation in the bottom of a wide valley, the refuge encompasses a portion of the headwaters of the Yaqui River, a major river system that drains western Chihuahua and eastern Sonora, Mexico.

Acquired by the U.S. Fish and Wildlife Service in 1982, the San Bernardino National Wildlife Refuge was established for the protection of endangered and threatened native fishes of the Yaqui River. Black Draw, which flows through the middle of the refuge, supports a diverse riparian forest of Fremont cottonwood and black willow.

Originally a 2,309-acre ranch, the area has had a colorful history due principally to the presence of water and these events have left their mark on the landscape of the San Bernardino area through vegetation changes and man-made structures.