GROINGRINDER, There are several flavors to dem files over the years (they keep changing the format.) - perhaps you are accessing dems that are not compatable with Bryce(either too old or more likely too new?) 3dem is free and will even seamlessly join two sequential dems and seems compatable with most of the differrent types of dem files. It's just easier for me to use 3DEM and convert to a more stable, in terms of number of flavors, format, instead of trying to import dem files directly into Bryce.