Buenos Aires National Wildlife Refuge in southern Arizona was established in 1985 for the reintroduction of masked bobwhite quail and the restoration of natural landscapes and their native wildlife, including the Sonoran Pronghorn. The 118,000-acre refuge lies in a broad Altar Valley between the Baboquivari Mountains, with their prominent main peak in the west, and the lower San Luis Mountains to the east. In the 1850s, Pedro Aguirre, Jr. built a homestead here in 1864 and named it Buenos Ayres, or "good air," because of the constant winds. His ranch changed hands several times before being purchased to form today's wildlife refuge. The refuge's visitor center is located in the adobe ranch house.
The refuge has over 80 designated campsites identified by a numbered sign. Camping is free and allowed for 14 days in a 30-day period, but only in the designated campsites. Most campsites have a fire ring/grill. Site sizes vary from a single vehicle to large enough for multiple RVs and trailers. Most are suitable for tents.
Fuel and limited supplies are available in the nearby small towns of Sasabe and Arivaca.
Choffo Tank, BANWR 204, goes east off Pronghorn Loop, climbing through grassland dotted with mesquite and groves of ocotillo cacti. The trail ends at BANWR 204, a road restricted to service vehicles only. Campsites 75 and 76 are near the west end of the trail. 75 is a sizeable pull-through site suitable for an RV, trailer, or several vehicles. 76 is tucked away beside a wash under mesquite trees. The site can accommodate one vehicle or a vehicle with a small trailer. Both sites have a fire ring/grill.