Water-resources data for Colorado for the 1996 water year consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of wells and springs. This report (Volumes 1 and 2) contains discharge records for 321 gaging stations, stage and contents of 26 lakes and reservoirs, 1 partial-record low-flow station, peak-flow information for 30 crest-stage partial-record stations; water quality for 135 gaging stations and for 11 lakes and reservoirs, supplemental water quality for 175 gaged sites; water quality for 34 miscellaneous sites and 14 observation wells; water levels for 2 observation wells, and meteorological data for 30 sites. Nine pertinent stations operated by bordering States also are included in this report. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey under the direction of W.F. Horak, District Chief. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies.