GeoGraphics
- Provides custom maps, drawings, and technical illustrations. Provides links to publications and images.
- http://www.btinternet.com/~simon_tapper/index.html

USGS NAWQA Digital Maps
- National Water-Quality Assessment provides digital maps for a variety of themes.
- http://water.usgs.gov/nawqa/digmap.html

Geology of Greenland Map Series
- Geological survey of Denmark and Greenland. All maps are compiled on CD.
- http://www.geus.dk/departments/geol-mapping/map-cd-rom/gr-map-cd-rom-uk.htm

Geologic Data Systems
- Works with petroleum companies to make precise geological maps.
- http://www.gdata.com/