Geographic Information Systems (GIS) data and resources

The following sites provide access to GIS shapefiles and other geographic data. Most of the links will direct you to external Web sites.

GIS Shapefiles	AdministrativeCounties, cities, townships, census tracts, and other areas for which socioeconomic data are tabulated U.S. Census Bureau HistoricalBoundary files for historical census data tabulations National Historical Geographic Information System (NHGIS) EnvironmentalGeology, hydrology, watersheds, land cover, elevation, and more Iowa Natural Resources GIS Library GeneralArcGIS shapefiles included with Iowa State University's ESRI site license (ISU login required)
Lists of geographic areas	U.S. GazzetteerGeographic identifiers, names, and coordinates for counties, cities, and other census geographic areas U.S. Census Bureau Geographic Names Information SystemNames and coordinates of cultural and physical geographic entities U.S. Geological Survey
Geographic correspondence	County-to-RegionCounty assignments to metropolitan and micropolitan areas and other administrative regions City-to-CountyCities by county