The Bureau of Reclamation (BOR) proposed to undertake geological investigations at Horseshoe Reservoir within Tonto National Forest as part of the Horseshoe-Carefree Seismic Hazard Study, a project aimed at investigating active and potentially active faults in central Arizona along the Salt and Verde Rivers to determine fault activity and slip rate to use in a probabilistic seismic hazard assessment. Investigations along the Horseshoe Fault consist of rock/soil sampling and natural exposure descriptions within 550 m of 20 generalized sampling locations selected along scarps east and southeast of Sunset Mountain. As the investigations constitute a federal undertaking by the BOR, the project is subject to Section 106 of the National Historic Preservation Act. The BOR contracted WestLand Resources, Inc. (WestLand) to conduct archaeological monitoring of the geological investigations for the Horseshoe Fault portion of the Horseshoe-Carefree Seismic Hazard Study.
A. D. Craig (Wed,) studied this question.