This data release is a compilation that presents water-quality data for the period October 1962 to September 1963 for the sites listed on page 2. These preliminary data are subject to revision before final publication in the annual series of U.S. Geological Survey Water-supply papers entitled Quality of surface waters of the United States. Most of the data were obtained as part of the Geological Survey's continuing program for the investigation of the nation's water resources or as part of a cooperative program with the U.S. Bureau of Reclamation; some data were obtained as part of cooperative programs with the State Engineer of Utah and with the Soil Conservation Service.