Contours with 1 foot intervals and related index files. This data can be searched by keyword or browsed by subject and are available in a variety of formats, including KML, WMS, GeoRSS, and Shapefile.

Direct link to download a geodatabase containing elevation contours for the entire state of Colorado at contour intervals of 10, 20, and 40. The most recent contour line was entered on 10/01/2009. Dataset is maintained by the U.S. Geological Survey.