I'm pretty sure that I am not getting the two confused. The confusion is the text on the valuation map. I've reproduced a small section of it here to show you. The D&RG depot is in the lower left corner. The engine house is in the center and I presume that it is D&RG but if you look at the text above the engine house track it is clearly labeled "Silverton Northern RR". The only conclusion I can make from this is that the house was shared with the silverton Northern. But that brings up a whole lot of questions for me. The val. map is from 1919 and corrected up to 1927.If the SN engine house was completed in 1912 per "The Rainbow Route" why would the SN need to share the other house? Why does the valuation map not shown the SN house or atleast the tracks to the house? There is certainly a lot of other SN track shown on the map.
Also note some of the other tracks labeled SN on the valuation map. In fact the siding next to the D&RG main (Tr 23) is labeled as joint use with SN further off to the left of this pic.
Dave