Quality of the ground water in the lower Colorado River region, Arizona, Nevada, New Mexico, and Utah

This atlas presents data on the areal and vertical distribution of the dissolved-solids and fluoride concentrations in ground water for the lower Colorado River region, an area of about 140,000 square miles in parts of Arizona, Nevada, New Mexico, and Utah. The maps were prepared using data from previously established reports, data collected by other Federal, State, and local agencies, and data from the files of the U.S. Geological Survey offices in Arizona, Nevada, New Mexico, and Utah. These data have been compiled as a part of the lower Colorado River region Type I framework study made in cooperation with the U.S. Bureau of Reclamation.