National GIS Data Resources:

• GeoCommunity GIS Data Catalog 
• Census 2000 TIGER/Line Data
• Geospatial One Stop
• NRCS Soils Data
• MSR Maps (formerly Terraserver – USA)
• NOAA HDSC (precipitation)
• National EPA GIS Data
• State GIS Data Clearing House
• State EPA GIS Data
• USGS Geographic Data Download
• USGS National Map Server

 

State GIS Data Resources:

• Chicago Area Geographic Information Study
• University of Chicago Center for Population Dynamics
• Illinois Natural Resources Geospatial Clearninghouse
• Illinois State Museum GIS Lab
• Inside Illinois
• GIS Data for IL from IDOT

Indiana:

• Indiana GIS Inititiative
• Indiana University GIS Library
• Indiana Map
• Indiana Spatial Data Portal

Iowa:

• Iowa Dept. Of Natural Resources GIS
• Iowa GIS Clearinghouse
• Iowa State University GIS

Kansas:

• Kansas Geological Survey
• Kansas Geospatial Community Commons:

Kentucky

• Kentucky Geography Network

Michigan:

• Michigan Information Center

Missouri:

• Missouri Spatial Data Information Service (MSDIS)

Wisconsin:

• WisconsinLand Information Clearinghouse
• Wisconsin Dept of Natural Resources GIS
• Wisconsin State Cartographer’s Office 
• Wisconsin View