more DEM questions

This is an "update" for my previous DEM question (sorry about the confusion)...

I was able to get m.dem.extract to create a viable raster layer from the
USGS 1-degree DEM from the downloaded file (which was copied to tape). The
only glitch is that only a single catagory was created which has "no data."

Is is possible to help GRASS create the necessary catagory information to
accompany the raster file?

Thanks (again),
Scott Grover
scottg@horne.com