It might be helpful to see larger versions of the images, if possible. The top image looks as if it might be earlier than 1906. Hard to tell given the size of the image on my screen, but the pilot looks as if it has a link and pin 'push bar' and long pilot. As an interstate carrier, the D&RG had to comply with the federal Safety Appliance Act which mandated automatic couplers and air brakes on equipment used in interstate service, effective in 1903. Also, note the predominance of hewn ties in the upper view, again suggesting some time earlier than 1903 if it is on the D&RG.
The country in the background in both views looks like some of that along a couple of the logging lines connecting to the D&RG in southern Colorado or northern NM.
Charlie Mutschler
-30-