SIERRA MADERA. Sierra Madera, a summit also called Madera Mountain, is a half mile east of U.S. Highway 385 and a half mile north of Number Four Draw in southwestern Pecos County (at 30°36' N, 102°55' W). The peak, at an elevation of 4,593 feet above sea level, rises 793 feet over the desert floor. Sierra Madera is an example of a cryptoexplosion structure, formed by the terrestrial impact of an extraterrestrial object. It was formed when massive limestone was drawn upward and inward by the collision. Its central uplift is five miles across, surrounded by a structural depression one mile wide and by an outer concentric rim a half mile wide. The peak stands in an area of recharge sand and caliche on sharply dissected flat to rolling terrain. Local vegetation consists primarily of oak, juniper, sparse grasses, some mesquite, hardwoods, scrub brush, creosote bush, and cacti. Sierra Madera is Spanish for "wooded hills."