Exactly. And this is the best photo, I research this area and there are many poorer copies but none better.
This is the 20" love from Clinton to Metcalf, Arizona Copper Company and Coronado Railroad. Taken in the early 1900's (1903 maybe? Don't have my reference material at hand right now) during the time that the line was being converted from 20" to 36". Note the 36" gauge box cars on the right background.
Photo location is just above the Longfellow Incline, looking north-ish. In other photos of the whole area, one can see the ore bins in the background.
Mike Conder