The DEM Loader allows you to load Digital Elevation Map files that have the same file format as the U.S. Geological Survey's standard DEM format. The DEM Loader will not accept Spatial Data Transfer Standard (SDTS) formatted data.
DEM files are available on the Web for a number of states within the U.S. For more information, refer to http://www.webgis.com/terr_us1deg.html
The DEM Loader first launches a multi-file selection dialog. After choosing one or more DEM files to load, you are presented with a simple dialog where you can set the I and J-skipping. For large DEM files, you may want to set both of these to be 10 or more.