Lechuguilla Desert border of the Gran Desierto de Altar of Sonora, Mexico. The Lechuguilla Desert lies to the east-northeast of the connected ranges, Gila Mountains, and north of the Tinajas Altas Mountains, which extend southeast into north Sonora. To the west and southwest of the two ranges lies the Yuma Desert. The Tule Desert (Arizona) lies east of the Lechuguilla, and the Cabeza Prieta Mountains; all three deserts are at the northwest perimeter of the great desert, the Gran Desierto de Altar, and the Pinacate Peaks volcanic field region. Lechuguilla Desert The Lechuguilla Desert is a small desert located in southwestern Arizona
Painted Desert (Arizona) desert is composed of stratified layers of easily erodible siltstone, mudstone, and shale of the Triassic Chinle Formation. These fine grained rock layers contain abundant iron and manganese compounds which provide the pigments for the various colors of the region. Thin resistant lacustrine limestone layers and volcanic flows cap the mesas. Numerous layers of silicic volcanic ash occur in the Chinle and provide the silica for the petrified logs of the area. The erosion of these layers has resulted in the formation of the badlands topography of the region. In the southern portions of the desert the remains of a