Bird-watchers consider Buenos Aires National Wildlife Refuge unique because it's the only place in the United States where they can see a "grand slam" (four species) of quail: Montezuma quail, Gambel's quail, scaled quail, and masked bobwhite. If it rains, the 100-acre Aguirre Lake, 1½ miles north of the headquarters, attracts wading birds, shorebirds, and waterfowl—in all, more than 320 avian species have been spotted here. The quail share the turf with deer, coati, badgers, bobcats, and mountain lions. Touring options include a 10-mile auto tour; nature trails; a boardwalk through the marshes at Arivaca Cienega; and guided bird walks, also at Arivaca Cienega (November–April, first Saturday at 8). A 3¾-mile guided hike in Brown Canyon is offered on second and fourth Saturdays, November–April (call ahead to reserve a spot). Admission and guided bird walks are free; Brown Canyon hikes cost $5. Primitive campsites are available without reservations. Pick up maps at the visitor center.