In cultural terms, the Southwest has never been satisfactorily defined. This is particularly true of the southern boundaries. Archeologists usually include the territory occupied by the groups we term Anasazi, Hohokam, Mogollon, and Patayan; it is this area that will be considered here.

Physiographically (Atwood 191+0; Darton 1925; Fenneman 1931), the northern and eastern parts of this area belong primarily to the Colorado Plateaus Province; the southern and western parts comprise a portion of the Basin and Range Province. Physiographers subdivide these major provinces into lesser units having more significance for the archeologist. The Colorado Plateaus Province is marked primarily by high mesas and plateaus underlain by nearly horizontal strata of strong, cliff-producing rocks locally covered by volcanic features or domed by igneous intrusions. This extensive area is drained largely by the Colorado River and its tributaries. Among the distinguishing features are the hundreds of deeply entrenched canyons and great retreating cliffs or escarpments.