Prehistoric agricultural adaptation and settlement in Long House Valley, Northeastern Arizona

A recently completed intensive archaeological survey of Long House Valley in northeastern Arizona has provided a detailed body of data on prehistoric settlement distribution and environmental variation. Long House Valley was occupied between A.D. 1 and 1300 by prehistoric agriculturalists referred to as the Kayenta Anasazi. This study examines the changing relationship between settlement locations and agricultural adaptations from A.D. 500 to 1300 in Long House Valley. As part of this analysis, the archaeological, ethnographic, and environmental background of the Kayenta region is reviewed as a basis for understanding the nature of agricultural adaptation in this region. Agricultural practices of the Hopi Indians of northern Arizona provide the basis for a model of probable agricultural field locations. This combined with an examination of the physiographic, hydrographic, and edaphic features in the valley allow identification of potential field areas. Changes in the potential of identified field areas are postulated on the basis of variation in available moisture as determined from a regional dendroclimatic reconstruction. Prehistoric habitation site locations and their changing distribution through time are examined against these proposed changes in field potential. This study demonstrates that there is a distinct positive correlation between settlement location and potential field location as determined by available moisture. Beginning about A.D. 1150 deteriorating environmental conditions in the form of decreased moisture, arroyo cutting, and lowered water table are considered the primary determinants of changes in site locations. These changes are viewed as an adaptive response by the Kayenta Anasazi to conditions of decreased moisture. Continuing deterioration of the environment made the practice of agriculture impossible and resulted in the total abandonment of Long House Valley and the entire Kayenta region by A.D. 1300.