HAT MOUNTAIN. Hat Mountain, named for its shape, is in east central Presidio County 2½ miles west of the Brewster county line (at 29°59' N, 103°51' W). The summit, at an elevation of 5,300 feet above sea level, rises 985 feet above the unpaved road along its southern edge. Hat Mountain is formed of volcanic tuffs and is surrounded by wash deposits of sands and gravels. The area is desert mountain terrain and rugged canyonland with loose surface rubble. Local vegetation includes sparse grasses, cacti, and desert shrubs of conifers and oaks.