Database fields in category Geographic location

	Distribution maps
Label	Lower 48	Alaska	Hawaii	Statistics	Description
`DATUM`					Datum of the geographic coordinates
`LATITUDE`					Latitude in decimal degrees
`LONGITUDE`					Longitude in decimal degrees (negative = West)
`QUAD24CODE`					Code for the USGS 1:24,000 (7.5 minute) quadrangle in which sample is located
`QUAD250COD`					Code for the USGS 1:250,000 (1x2-degree) quadrangle in which sample is located
`QUAD100COD`					Code for the USGS 1:100,000 (1:62,500 in Alaska) quadrangle in which sample is located
`FIPS`					FIPS of county calculated from geographic coordinates
`HUC_8`					8-digit hydrologic unit code calculated from geographic coordinates
`QD250NAME`					Name of USGS 1:250,000 (1x2-degree) quadrangle in which sample is located
`ZIP3`					The zip code where the sample was taken. Three most significant digits only; if the full zip code would be 20192, this field wi
`CONGDIST`					Unique identifier for the US congressional district from which the sample was taken.