The Roosevelt Community Development Study: New Perspectives on Tonto Basin Prehistory

The Roosevelt Community Development Study (RCD) involved the testing and excavation of 27 sites in the Lower Tonto Basin of central Arizona. This is one of three related data recovery projects undertaken in the Tonto Basin for the Bureau of Reclamation prior to the raising of the Roosevelt Lake dam. The results of the RCD project are presented in four Anthropological Papers of the Center for Desert Archaeology. This volume synthesizes data recovered from the RCD excavations to provide a more inclusive view of the prehistoric occupation of the RCD project area and the Tonto Basin. This includes the integration of data produced by approximately 20 person-years of fieldwork. More than 150,000 artifacts and 300 botanical samples were recovered and analyzed, and reams of nonartifactual data dealing with architecture and other feature types and deposits were produced. Basic site descriptive data and the results of artifact analyses and botanical studies have been presented in previous RCD volumes and are synthesized in the various chapters of this volume. These data are used as a vehicle for discussing a number of issues central to our present understanding and future study of Tonto Basin prehistory. These include issues related to the scale of local systems; the impact of effective environment; processes of migration, interaction and integration; and the significance of cultural diversity.

To briefly summarize, our findings suggest that the Lower Tonto Basin was inhabited between the second and seventh centuries by an indigenous, ceramic-using population that probably derived from local Late Archaic groups. This population had the closest affinities with contemporaneous groups in the Mogollon Highlands and was distinct from groups within the Phoenix and Tucson basins. Phoenix Basin groups, probably from the Gila River area, migrated into a sparsely populated Tonto Basin sometime during the Colonial period of the eighth century and established a permanent settlement at Meddler Point. The Meddler Point settlement slowly expanded and interacted with local Tonto Basin groups over the next 250 years, but it still participated in the Hohokam regional system. Relations with the Phoenix Basin area were curtailed at some point during the eleventh century, when the Hohokam regional system retracted and was reorganized. The retraction of that network, along with the expansion of the Chaco system, resulted in increased interaction of Tonto Basin populations with groups to the north and east of the Basin that were producing Cibola Whiteware ceramics. An increase in cotton production in the Tonto Basin at approximately the same time suggests that cotton may have been exchanged for whiteware vessels.

Following established trade connections, migrant pueblo populations entered the Lower Tonto Basin in the mid-to-Iate thirteenth century Classic period. Migration into the Tonto Basin was probably in response to environmental stress and conflict in various portions of the northern Southwest. The presence of diverse cultural groups, an increasing population to feed, and communication needs are suggested reasons that local populations constructed platform mounds around A.D. 1280. Platform mounds in the RCD project area are believed to be nonresidential, integrative features with a religious or ideological focus. For reasons unknown, but most likely related to continuing environmental and social stress, this system failed within 50 years. All settlements within the RCD project area were abandoned by A.D. 1325. Some groups probably moved to the large settlement at Schoolhouse Point excavated by Arizona State University; most of the population, however, apparently left the eastern Tonto Basin at this time.