Okay, this is not narrow gauge, but it's on the line that used to be narrow gauge. This was the last segment of the old DSP&P in operation. It was standard gauged in 1943 and ran freight until 1986. It became a tourist line in 1988.
I got to correspond with one of the engineers on the Leadville, Colorado & Southern about some track work on the old South Park Line to Climax.
Here is a post about the work earlier this year that helped get their trains to the farthest end of their line, not far from Climax and the Molybdenum mine. He let me use a bunch of his great photos too, including shots of work on the track.
Kurt
Train at the farthest edge of the LC&S line, not far from Climax-Sean McBride photo