BOFECILLOS MOUNTAINS. The Bofecillos Mountains are surrounded by Bofecillos Canyon on the north, Tapado Canyon on the southeast, and Redford Bolson on the south and southwest, in southern Presidio County (at 29°27' N, 104°05' W). Their elevations range from 4,922 feet above sea level (Panther Mountain) to 5,137 (Oso Mountain). The Bofecillos are composed of conglomerate, sandstone, tuff, and basalt. Loose rubble covers their surface. The surrounding desert mountain terrain is cut by numerous rugged canyons. Sparse grasses, cacti, and desert conifers and oak shrubs grow in the area. In 1852 the boundary survey expedition of Maj. William H. Emory passed through the Bofecillos Mountains.