Theodore Roosevelt Dam and Lake Roosevelt

This collection contains the three mitigative data recovery studies that the Bureau of Reclamation funded to investigate the prehistory of the Tonto Basin in the vicinity of Theodore Roosevelt Dam. The research was necessary to mitigate any adverse effects related to modifying and raising the height of the Theodore Roosevelt Dam in the Tonto Basin. The original dam, completed in 1911, is used to store water (for municipal and agricultural use) and to generate electricity for the Phoenix metropolitan area. Most of the sites included in the investigations are located above the level of the original reservoir, at elevations between 2,120 and 2,200 feet. The modifications to the dam were designed to improve the structure for controlling floods. During such flood events, the reservoir could potentially rise 80 feet above its usual elevation of 2,120 feet, which would temporarily inundate many of the sites included in these studies. As the floodwaters drain (generally in a matter of days), the water will recede to its normal level (or less, as water is used for municipal, irrigation, and power-generating purposes).

A planning team planning team composed of archaeologists from the Bureau of Reclamation, Tonto National Forest, and the State Historic Preservation Office developed a program of multiple, parallel projects to complete the mitigtation studies for the Roosevelt Dam modifications. The goal established by the planning team was to treat the prehistoric sites as part of regional systems. Most of the research effort was directed at sites that lay within the limits of the expanded reservoir, but sites beyond the reservoir were also included. This was in part because the improvement of recreational facilities at the reservoir would attract more people to the area, which would increase the potential for disturbance to sites throughout the region. The planning team also recognized that understanding the large sites within the area of the expanded reservoir was enhanced by the collection of data from smaller sites lying in the secondary zone of increased recreation use surrounding the reservoir. Each of the three mitigation projects examined one or more clusters of sites at different locations around the reservoir.

"The Roosevelt Platform Mound Study" focused on sites of the Salado period, especially on platform mounds and the residential compounds clustered around the mounds. The Arizona State University Office of Cultural Resource Management (OCRM) conducted the work for the platform mound study. A second project, "The Roosevelt Community Development Study", examined the developments that took place in the centuries leading up to the appearance of platform mounds. This research was conducted at a series of sites on the northern bank of the Salt River opposite the Roosevelt Platform Mound Study's Pinto Creek Complex sites. Desert Archaeology, Inc. conducted the work for the Roosevelt Community Development study. The third project, "The Roosevelt Rural Sites Study", examined small sites located away from the larger prehistoric villages for the purpose of determining the importance of nonriverine settings in the adaptive strategies of the people of the Tonto Basin. It involved work at six different locations around the perimeter of Roosevelt Lake. Statistical Research, Inc. completed the research for the third study.