Water-resources data for the 1972 water year for Wyoming include records of data for the chemical and physical characteristics of surface and ground water. Data on the quality of surface water (chemical, temperature, and sediment) were collected from designated sampling sites at predetermined intervals such as once daily, weekly, monthly or less frequently. At some sites water-temperature data were recorded on charts by recorders. Data are given for 138 sampling stations of which 112 are continuous-record stations and 26 are miscellaneous sites. Chemical analyses also are given for 127 ground-water sites. Locations of surface water-quality stations are shown in figure 1 and locations of ground-water sites are shown in figure 2. These data represent that portion of the National Water Data System collected by the U.S. Geological Suryey and cooperating State and Federal agencies in Wyoming. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey under the direction of Robert L. Cushman, district chief. Wyoming district personnel who contributed significantly to the collection and preparation of data included in this report were: E. R. Cox, S. A. Druse, W. G. Hodson, M. E. Lowry, D. J. O'Connell, G. W. Armentrout, Jr., M.A. Crist, B. H. Ringen, W. B. Borchert, W.R. Glass, G. C. Lines, H.B. Fabricius, P. B. McCollam, C. E. Obert, K. G. Polinoski, T. W. Custis, R. L. Muench, J. O. Ragsdale, M. D. Stevens, R .. C. Baumann, D. W. Brownell, R. V. Foresman, J.M. Johnson, J. L. Lynch, M. L. Smalley, and J. P. Kyner.

The Geological Survey has published records of chemical quality, water temperatures, and sediment since 1941 in an annual series of water-supply papers entitled, "Quality of Surface Water of the United States." Beginning with the 1964 water year, water-quality records have been released by the Geological Survey in annual reports on a State-boundary basis. These reports are for limited distribution and are designed primarily for rapid release of data shortly after the end of the water year. These records will be published later in Geological Survey water-supply papers.