GIS Data and Websites

Search either the raw data catalog or the geospatial data catalog.

An extremely useful site - you can create your own maps as well as download data. Detailed information about the United States, including health, environment, transportation, agriculture, etc.

Base maps available for noncommercial use.

Public domain map data, vector and raster, at varying scales.

Boundaries and DRGs.

(Beta) Integrated population and environmental data.

Produced by the National States Geographic Information Council (NSGIC); tracks data availability at state and local government level.

Free aggregate census data and GIS-compatible boundary files for the United States between 1790 and 2010.

Excellent portal website with background information and links to projects and databases.