The Permian is represented in the southwestern United States by limestones and sandstones, the latter in part red, and local deposits of gypsum and salt. In Arizona the principal formations are the Kaibab limestone, Coconino sandstone, and the greater part of the Supai formation. Part of the Naco limestone in the southern part of the state is Permian and strata of that age have been found in the southwestern part of the state. In the Holbrook dome and Defiance uplift the Kaibab limestone thins out and the Coconino sandstone is extensively exposed while in part of this area the red beds of the Supai formation lie on pre-Cambrian granite and quartzite.

In New Mexico these strata are represented by the Chupadera formation consisting mainly of limestone, gray and red sandstone, and gypsum, and the red Abo sandstone. The latter lies on limestone of the Magdalena group (Pennsylvanian) but overlaps locally on pre-Cambrian rocks notably in Zuni, Nacimiento, and Pedemal mountains. Under much of eastern New Mexico the Chupadera formation includes thick deposits of salt and anhydrite. To the south the formation merges laterally into the limestones and sandstones of the Guadalupe group which carries a large and remarkably different fauna. This change of life indicates a great change in environmental conditions in a short distance which is difficult to explain. Over the Guadalupe and Chupadera strata lie the thick Castile gypsum and the Rustle limestone, which are probably also of Permian age.