KartoMNT is a free software of height model digitalization.
This software allows you to create your own Digital Height Models (DHM) with a simple map. Then you'll be able to visualize DHMs with the KartoMNT 3D viewer.
Use map data to plan hikes or explore new areas. Includes 3D maps of terrain rendered in real-time; trace trails across the terrain and get height verses distance profiles; tile together adjacent maps to create seamless map areas. Reads USGS SDTS files.