The Chihuahuan Desert sits across the U.S.-Mexico border, and comprises approximately 140,000 square miles. In the U.S., the desert stretches just north of Albuquerque, New Mexico, and into Texas west of the Pecos River. It encompasses the northern half of the state of Chihuahua in Mexico and most of the state of Coahuila. Higher in altitude than its neighbor to the west, the Sonoran Desert, the Chihuahuan Desert ranges in elevation from 1,500 feet to about 5,000 feet. It has been described by the World Nature Fund as perhaps the most biodiverse desert in the world.