SiteNumber - unique identifier for the field site SiteName - descriptive name for the field site SiteComment - miscellaneous comments about the field site ProjectCode - code for project that established the field site PP_Site_Label - label used for the field site in USGS Professional Paper P1652 AMLI_Analysis_ID - identifying number used to group field sites that are logically co-located for analysis purposes Longitude - longitude of field site location Latitude - latitude of field site location UTM_Easting - UTM easting of field site location UTM_Northing - UTM northing of field site location Stream - indicates the stream on which the field site is located, if anySiteNumber, SiteName, SiteComment, ProjectCode, PPSiteLabel, and Stream were all provided by the project scientists who collected the sample data. Logically co-located sites were determined by project scientists. UTM easting and northings were added to the FIELD_SITES.PAT file using the ArcInfo ADDXY command. Longitude and latitude values were calculated using the ArcInfo PROJECT command.