The Triangle Bar Ranch, located along Highway 77 just north of Mammoth and approximately 50 miles north of Tucson, includes an 8-mile perennial stretch of the San Pedro River, with portions of the property located at its confluence with Aravaipa Creek. Both waters are of critical importance to native fish species in Arizona such as the Gila topminnow and Gila chub. The Ranch holds many significant wildlife values including habitat for both the endangered Southwestern willow flycatcher and loach minnow, and the presence of active beaver dams make the property particularly important.
The Ranch is also rich in Arizona history, containing portions of the Old Camp Grant Military Reservation and including Putnam Spring in Camp Grant Wash, a popular spot for hikers and birders.
The Arizona Game and Fish Department acquired the property utilizing both Arizona Heritage Funds (from state lottery ticket sales) and U.S. Fish & Wildlife Section 6 Funds for the protection of endangered species.