Previous attempts to validate general circulation model simulations of land surface hydrology have often been limited by the absence of systematic historical data, especially for runoff, precipitation, and temperature. Because hydrological response times for unregulated watersheds in the United States vary from a few hours to a few days at most, climatological studies dealing with land surface hydrology require data at relatively short time intervals. We describe a set of 1009 U.S. Geological Survey streamflow stations, and 1036 National Oceanic and Atmospheric Administration climatological stations, for which long-term (1948–1988) observations have been assembled into a consistent daily data base with missing observations estimated using a simple closest-station prorating rule. Care was taken in selection of the streamflow stations to assure that the records were essentially free from regulation. The climatological stations are a subset of the historical climatology network for which monthly data are described by Quinlan et al. (1987). The data format is provided to facilitate development of alternative data retrieval algorithms, Estimated values for missing data, as well as suspicious observations, are flagged. The data are retrievable by station list, state, latitude-longitude range, and hydrologic unit code from compact digital read-only memory (CD ROM). CD-ROM copies are available from the second author.