This report on the quality of surface water in the Virgin River basin from the headwaters near Navajo Lake, Utah, to Littlefield, Ariz., was prepared by the U.S. Geological Survey in cooperation with the Division of Water Rights, Utah Department of Natural Resources. The objectives of the study leading to the report were to obtain information on general chemical characteristics of surface water and to determine effects of the natural environment and water use on these characteristics. The scope of the study did not include an intensive investigation of the effects of man's activities on water quality.