John,
I'm trying to place this shot on one of the maps Dave Grandt posted in your 'Durango trackage map' post from 10 days ago. That's the highway bridge we see to the left, and just left of that is the RR bridge to the old RGS. The old loop goes off to the right with a spur off that past the mill and beyond. From where you took the shot you could turn to the right and a little behind and the roundhouse is right there, correct?
It's a great pic because it IS history. For every photo "published" there could be dozens deemed lacking in composition, lighting, or some other aesthetic quality - but are incredibly rich in content. Keep 'em coming!
From another angle, as much as I appreciate the rolling stock shots in 'Narrow Gauge Pictorial: Volume III', it's the edges of the photos that draw my attention, all that collateral information we may tend to overlook. For every photo I see of scenes that no longer exist, I always wonder what incredibly valuable shots were on the roll right before and after that shot.
Mike