For some fantastic tutorials and resorce links (including DEMs & Apps) check out thie site below. These tuts were done by Tom Patterson of the U.S. National Park Service and are well worth your time (one of the only things worthwhile for the average Joes' tax dollar). Make sure you see the link at the bottom for the "ICA Mountain Cartography Workshop" where you can obtain a great Bryce model of Mt Hood composed of 4 DEMs and colorized DOQs (it's around 14.2 megs). DEM Tuts & Info- http://www.nacis.org/cp/cp28/resources.html Bryce model- http://www.nps.gov/carto/hood/Bryce/Mt_Hood.br4