Jessica:
All of the Colorado counties that had D&RG trackage have these maps on file for legal and tax purposes. The ones I have for the third division were dated 1919 and the county clerk made microfilm copies for me (this was several years ago). The maps were too large to fit on a standard copy machine. Later, I put the microfilms in a film scanner and got a pretty good copy that way. They showed every building, every bridge, everything with dimensions.
The only problem with the maps, they were made for the county and only show the trackage in that county.