From Native American Information Superhighway Alltribes™ Wiki
Patayan (AD 875 to modern times): The name Patayan comes from the Yuman, "old people," used to describe prehistoric cultures that once flourished west of the Hohokam region and north to the vicinity of the Grand Canyon. Patayan is still inadequately defined entity. Various alternative terms have been proposed, together with several much discussed cultural stages.
This very broad-brushed, general developmental scheme masks a great deal of cultural variation, and not adequate to describe such variation accurately, nor to plot or evaluate the complex paths of culture change throughout the prehistoric Southwest. It was put together long before the advent of radiocarbon dating, and much of it developed while dendrochronology was still in its infancy. Nevertheless, the scheme is useful as a basic frame of reference. generations of scholars have developed local chronological and cultural sequences under its umbrella. Tree-ring and radio-carbon chronologies and these frameworks have provided the basis for the much more sophisticated ecological, regional, and settlement studies that have been characteristics of Southwestern archeology in recent years. A combination of all these approaches forms the portrait of Southwestern prehistory that follows.