This page provides links to free Geographic Information Systems (GIS) common data types. It is broken in to four sections. First, there are links to University of Oregon Social Science Instructional Labs (SSIL) web pages containing or with further links to GIS data on external sources. The second section contains links to datasets for Oregon, while the third section has links to United States datasets. The final section provides links to spatial datasets that do not fit in the categories above.
This page is meant to be a starting point for finding and acquiring GIS data, and it is not an exhaustive list of free GIS data on the world wide web. However, as with any information you obtain, you should always critically question any GIS data you obtain and use, whether from the World Wide Web or otherwise. For example, you should ask where data came from, who produced it, what errors or omissions it might contain, and so on.
The links below are to University of Oregon web sites containing GIS data.
The links below are to web sites containing GIS data of various spatial extents: