SANTIAGO MOUNTAINS. The Santiago Mountains are a narrow range, less than one mile wide for much of their length, running from the northwest to the southeast for thirty-two miles from Del Norte Gap, twenty miles south of Marathon, to the Big Bend National Park four miles southeast of Persimmon Gap in central Brewster County (centered at 29°48' N, 103°19' W). The Del Norte Mountains to the northwest and the Santiagos cross much of northwestern and central Brewster County. The highest point in the Santiagos is Santiago Peak, with an elevation of 6,524 feet above sea level. The Santiago Mountains have shallow, stony soils that support oak, juniper, and some mesquite.