TransDEM is a complete program suite for generating DEM models, which includes a module for generating DEM terrain directly into Trainz. Actual US DEM data, for any state in the US can be downloaded for free from the USGS seamless server.The program is accurate, easy to use, and a most powerfull tool for any Trainz route creator. However, be warned.........there is a steep learning curve to grapple with. The program includes tools for overlaying old and new USGS topo maps as well as Google Earth images directly onto generated DEM's.
Well worth the $32!