Data on geology, topography, hydrology, climate, land use, and vegetation were compiled between October 2000 and September 2001 and assembled into a database for use by local and regional waterresource managers and for future water-resource investigations. The hydrologic data include information on wells, springs, streamflow, water chemistry, and water use. Limitations of the data and additional data needs also were prepared. The roughly 5,000-square-mile Coconino Plateau contains a complex regional aquifer that has become increasingly important as a source of water supply for domestic, municipal, and in-stream uses owing to population growth and development. The flow characteristics of the regional aquifer are poorly understood because the aquifer is deeply buried, which limits exploratory drilling and testing, and because the geologic structure, which controls the occurrence and movement of ground water, is complex. The study area is about 10,300 square miles and, besides containing the entire Coconino Plateau, includes parts of adjacent areas where ground water from the Coconino Plateau discharges. Selected data are presented in tabular or graphical form. All data are available in electronic form.