The U.S. Department of Energy (DOE), through its National Energy Technology Laboratory, established a national program to evaluate the feasibility of separating carbon dioxide (CO2) from industrial sources and pumping it underground for long-term storage or disposal. This program was established in response to concerns that CO2 emissions from fossil-fuel combustion, and from other industrial processes such as cement production from limestone, are increasing atmospheric CO2 concentration and solar-energy absorption, thereby causing global warming. Carbon dioxide removal from industrial sources and storage in geologic reservoirs is known as “geologic sequestration.” A major aspect of the DOE program is to evaluate subsurface geology to determine the potential of underground rock formations for long-term CO2 sequestration. The West Coast Regional Carbon Sequestration Partnership (WESTCARB) is a consortium of seven western U.S. States and one Canadian Province that is one of seven regional North American partnerships established to evaluate technical aspects of high-volume CO2 capture and sequestration. Collaborative WESTCARB research programs have included more than 90 public agencies, private companies, and non-profit organizations. The Arizona Geological Survey began work in 2010 on WESTCARB Phase III – Arizona Geological Characterization. This report represents an initial WESTCARB assessment of CO2 storage potential in the first of ten identified Cenozoic basins in Arizona (Spencer, 2011), the Safford basin, and is part of Tasks 2 and 3 of Arizona WESTCARB Phase III (California Energy Commission Agreement Number 500-10-024). A supporting document and interactive PDF of the Safford Basin provided by Brian Conway (Arizona Dept. of Water Resources).