Although hunter-gather periods account for about 80% of prehistory in the Southwest, time-depth and the nature of mobility-based adaptations create a somewhat ephemeral material record. In the Phoenix Basin of Arizona, deep alluvial accumulations and the nation’s fastest growing large city exacerbate the situation. There is also some thought that parts of the Sonoran desert may have lacked sufficient resources for late Pleistocene human groups. However, these earlier periods mark the ingress trajectory for the introduction of agriculture to the Southwest. They are the platform upon which are based discussions of the social complexity that emerges from the adaptation to agriculture through European contact.

Current ecological relationships have been in place here for only the last 4,000 years. Compiling results from decades of CRM projects in a GIS context of reconstructed paleo-environments suggests a Paleo-Indian presence and begins to show Archaic landuse patterning. We included the Tonto Basin in our research area to increase the elevational range upon which ecological communities in the Southwest are based. The Tonto Basin was the site of the decade-long Roosevelt Platform Mound Study conducted by the Archaeological Research Institute at Arizona State University. This also gave us two of the most archaeologically significant Hohokam areas in Central Arizona.

In contrast to the Phoenix Basin, where late Pleistocene sediments currently lay under meters of alluvium, Pleistocene alluvial fans thought to have been preferred by hunter-gatherers in the Tonto Basin were down-cut and washed away long ago. To create the database for a paleo-environmental reconstruction in two basins where the paleo-sediments are either unreachable or no longer there, we relied on packrat middens and downloaded data from the 30 nearest middens (shown in blue above) using: North American Packrat Midden Database...............................................................NEXT >>