The U.S. Geological Survey (USGS) operated hydrologic data collection stations during fiscal yr 1985 in response to the needs of all levels of Government for hydrologic information. Surface water discharge was determined at 11,076 stations; stage data on streams, reservoirs, and lakes were recorded at 2,141 stations; and surface water quality was determined at 4,166 stations. Groundwater levels were measured at 39,301 stations, and the quality of groundwater was determined at 9,263 stations nationwide. Data on sediment were collected daily at 212 stations and on a periodic basis at 1,027 stations. Information on precipitation quantity was collected at 921 stations, and the quality of precipitation was analyzed at 108 stations. Data collection platforms for satellite telemetry of hydrologic information were used at 1,520 USGS stations. Funding support for the hydrologic stations was derived either solely or from a combination of three major sources--the Geological Survey 's Federal Program appropriation, the Federal-State Cooperative Program, and reimbursements from other Federal agencies. (Author 's abstract)