The Chihuahuan Desert (Spanish: Desierto de Chihuahua, Desierto Chihuahuense) is a desert and ecoregion designation covering parts of northern Mexico and the southwestern United States. It occupies much of West Texas, the middle and lower Rio Grande Valley, the lower Pecos Valley in New Mexico, and a portion of southeastern Arizona, as well as the central and northern portions of the Mexican Plateau. It is bordered on the west by the Sonoran Desert and the extensive Sierra Madre Occidental range, along with northwestern lowlands of the Sierra Madre Oriental range. On the Mexican side, it covers a large portion of the state of Chihuahua, along with portions of Coahuila, north-eastern Durango, the extreme northern part of Zacatecas, and small western portions of Nuevo León. With an area of a