CompuServe Thread

Was not aware of the SURF program. Don't know if it will read a DEM successfully. It would be slick if it did. The one thing to keep in mind is that USGS DEM files come by the quadrangal, a 1:24000 scale. Unless you are working with a relatively small area of land you will probably need to combine several DEM's together. This involves using either a GIS or Autocad to put the files side by side and connect all of the elevation lines together. While this is certainly easier than sitting around with a topo map and a digitizing tablet and puck tracing topo lines for hours, it is still a labor intensive task. If SURF will take a DEM directly and you don't want to play with registering a bunch of DEM's together you might try calling a university that has a cartography dept. They may have the DEM's you want already registered, or be willing to do the work with some overworked undergrad student for a nominal fee as a project. Other sources are companies that contract vegatative and soils survey work, architects that use CAD extensively, and possibly one of the US Government Land Management Agencies in your area like the Bureau of LAnd Management, US Forest Service, Army Corps of Engineers, etc. They all maintain extensive GIS systems, (particularly the USFS) and might be willing to share the files or sell them. Let me know if SURF works. Had not even thought of that! Dave