The Sonoran pronghorn (Antilocapra americana sonoriensis) is one of the most endangered ungulates in North America. The use of water to improve its habitat in southwestern Arizona has been limited in part because published reports claimed these desert ungulates do not use freestanding water. Because free-standing water has been beneficial to habitat improvement of other desert ungulates, we set up cameras at anthropogenic waters to see if they were used by pronghorn, examined literature and agency files related to Sonoran pronghorn and water, and interviewed ranchers who have lived and managed livestock in Sonoran pronghorn habitat since the 1930s regarding their observations of pronghorn use of livestock waters. Using direct observation and photographic evidence, we documented Sonoran pronghorn drinking freestanding water. Published reports claiming that Sonoran pronghorn do not drink were erroneous. Ranchers, agency files, and biologists from numerous state and federal agencies documented Sonoran pronghorn drinking. Federal and state agencies should be aggressive in examining how water developments can be used to assist in recovery of endangered Sonoran pronghorn.