Water resources data for the 1975 water year for Missouri consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs. This report contains discharge records for 138 gaging stations; stage and contents for 6 lakes and reservoirs, and water quality for 53 gaging stations. Also included are data for 103 crest-stage partial-record stations, 30 partial-record water quality stations and 25 miscellaneous sampling sites. 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 Missouri.