I am still getting an error when I try to mesh the two dem files (I tried re-downloading so I only had two to worry about) Should it matter if I'm using geographic or UTM projection? When I set it to UTM it will mesh them but there's a big gap between them, but if I leave it at geographic it gives me the message "DEMs Have Differnt Elevation Resolutions" which shouldn't be the case at all. I'm using the latest version of 3dem so I'm not sure what it doesn't like.