CARRIZO MOUNTAIN. Carrizo Mountain, the tallest peak in the mountain range of the same name, is twenty-four miles southeast of Sierra Blanca in southeastern Hudspeth County (at 31°04' N, 104°55' W). It has an elevation of 4,874 feet above sea level. Some of the oldest Precambrian rocks in Texas, about a billion years old, can be found at the surface in the Carrizos. The shallow, stony soils that form the land surface support scrub brush, creosote bush, cacti, grasses, oak, and mesquite. Carrizo is Spanish for "reed grass."