This report is one of several from Statistical Research Inc. written to develop the Cultural and Historic Resources Element of the Sonoran Desert Conservation Plan. Divided into four parts, the report summarizes available information that reflects the experience of (1) ancient peoples of Southern Arizona; (2) indigenous peoples; (3) non-indigenous peoples of the historical period; and (4) Pima County today.

This study covers the time period after 1200 A.D. in terms of the domestic landscape, the agricultural landscape, and the social landscape as the residents of southern Arizona adjust to upheaval and change in environmental and social conditions. This memorandum summarizes the study about the Classic Period and provides a comparison of findings and theories about area residents from both before and after 1200 A.D., which is the approximate time frame of the collapse and restructuring of cultural landscapes.