This tabular file contains water-quality information for stream sites in the spatial layer 'USGS_stream_sites'. The surface-water-quality information was collected by the U.S. Geological Survey (USGS) in the upper Washita River basin in southwestern Oklahoma from 1925 to 2005 and was retrieved from the USGS National Water Information System (NWIS) database in September 2005.
Each water-quality constituent in this tabular file has an attribute 'STAID' that relates to a site in 'USGS_stream_sites'. The tabular file 'USGS_codes' contains the parameter coding descriptions for the environmental data collected and descriptions of the analytical methods used.