kmaechner wrote
...I forgot to mention that Poor's 1965 comment was in reference to the old switchback...
That is definitely plausible. I based the switchback on the overlay on the early USGS map, which is a very small scale so not very precise, but there is a grade in about the right spot which I assumed to be the upper part of the switchback. The current access road follow it for a distance, and it is still visible heading toward the tailings pond dam above where the access road connects. The grade in this spot is relatively gentle, unlike the steep parts of the access road above it, so it does seem to be RR grade, and as it's above the later grade it was probably part of the switchback.