I recently came across this map of the Chapel Hill Iron Mine in an 1892 publication on mining in North Carolina. The Chapel Hill Iron Mine was operated by Gen. Robert F. Hoke, supposedly from about 1872-1882 and was a critical factor in how and where the rail line into Carrboro was built. Alternate connections to Durham, Hillsborough or Apex were considered, but connecting to University Station was the cheapest route and involved passing by Gen. Hoke's mine, so he put forward significant resources to make it come that way.
The map gives an interesting view into the workings of the mine. It shows the two main shafts (one of them already collapsed in 1892), which are now in the center of the Ironwoods neighborhood in Chapel Hill. I have previously found references (Orange County Observer, 10/23/1881) to a spur connecting from the rail line to the mine, but this map is the first time I have seen any indication of where it was. Apparently it went down the gully between Cardiff Place and Birchcrest Place. The 3’ gauge railroad must have wound back to the NW in order to connect with the main rail line without crossing Bolin Creek, so I suppose it must have followed a route like this:
The two red dots are supposed to be the locations of the shafts. I wonder if any remaining evidence of this narrow gauge railway can still be seen out there today?
UPDATE: Sure enough, we hiked up along the tracks just north of Bolin Creek and immediately found the abandoned grade. It looks like a good amount of work was involved in building up the grade for the spur and at least one small trestle must have been used. The spot where my gradual swooping curve takes a northward indentation was drawn to follow the contours on the topo map, but actually a trestle bridged that cove. In a couple of places, the OWASA sewer lines tore up the former railroad grade, but the grade is mostly intact and quite discernible.
Here's a picture of the historical marker at the top: