I grew near this area. In the 70s and 80s the track was still in place down to the lime mine. It was standard gauge, not narrow. I don't remember any trains going down the track though. They'd use the siding at the junction (near where South Shingle Rd crosses the track for the 2nd time going south) where the track came in to the mainline to switch cars though. I can remember hearing cars being slammed together when I was a little kid and we were over a hill from there.
We called the area where they switched cars the 'Vidabark' Mine, though it wasn't a mine at all. It was used to process bark from logging operations elsewhere, and used to ship on the railline too. The track to the lime mine was ripped out sometime during the 90s and the roadbed was converted in to a road that served the newly developed ranchettes in the area. The 'Vidabark' Mine also had a spur next to the siding where gondolas were loaded, and I believe its still there buried under gravel and dirt, just disconnected from the main. The 'Vidabark Mine' shut down sometime in the 80s from what I remember.