Water-resources data for the 2004 water year for California consist of records of stage, discharge, and water quality of streams, stage and contents in lakes and reservoirs, and water levels and water quality in wells. Volume 3 contains discharge records for 187 gaging stations, stage and contents for 48 lakes and reservoirs, water quality for 35 stations and 14 partial-record stations, and precipitation data for 2 stations. Also included are 1 miscellaneous partial-record site and 1 crest-stage partial-record station. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.