Carbon capture and storage (CCS) technologies could playa critical role in mitigating the impact of fossil fuel-based electricity generation on greenhouse gas (GHG) build up and resulting climate change. The Public Interest Energy Research (PIER) program continues to conduct research to define least-cost GHG mitigation strategies including an assessment of the potential for CCS. In parallel, the U.S. Department of Energy (DOE) is actively engaged in geologic CCS projects through a network of regional partnerships, including the West Coast Regional Carbon Sequestration Partnership (WESTCARB) currently administered by PIER. The Arizona Geological Survey (AZGS), working in conjunction with Southwest Regional Carbon Sequestration Partnership, previously evaluated the CO2 storage potential in Arizona. Characterization of potential deep formations in northern Arizona was limited to a radius of about 50 miles from existing power plants.Additional assessment and characterization of the CO2 storage potential in deep basins and saline formations throughout the state of Arizona will extend and complement the earlier AZGS evaluation which provided estimates of geologic storage potential throughout the state of Arizona.