RATTLESNAKE MOUNTAINS. The Rattlesnake Mountains are a rugged, roughly circular group of peaks that straddle the boundary of Big Bend National Park five miles southeast of Terlingua in southwestern Brewster County (at 29°15' N, 103°33' W). The elevation at the highest point within the Rattlesnake Mountains is 2,911 feet above sea level, and the mountains rise as much as 600 feet above Terlingua Creek, which skirts the base of the range on the north and west before it crosses the broad desert flats to the southwest. The higher elevation of the Rattlesnake Mountains relative to the surrounding desert is a result of the markedly different levels of resistance to erosion between the hard volcanic rock and the soft surrounding sedimentary material. The biological community at the Rattlesnake Mountains is characteristic of a Chihuahuan Desert scrub habitat. Several species of rattlesnake are indigenous to the area, and this probably accounts for the name of the mountains.