The 4th tunnel heading toward North Carolina in Doe River Gorge is just past a dilapidated deck truss bridge over the Doe River. It’s crossable. Careful, though. The tunnel is centered at36.250708, -82.156534 and it’s filled with water. (read the comment on this)
There are two bridges over the Doe in the Gorge. One still has a truss superstructure, but precious little else and the other is as described above.
Blogging the Railroad Tunnels 
Tunnel 4 is dry in the wintertime. As you’ll find on up at tunnel 5, at old MP 19.7, it IS filled with water and the east portal has collapsed. The west portal has partially collapsed creating a dam that has filled the tunnel with water. Be careful up there on the old grade past tunnel 4.
Thanks, Mike. We’ve been through here twice, once in winter from the Ministry side and once in early spring from the railroad grade side. This was before I was doing a reasonable job of GPSing tunnel locations (I hadn’t even thought of doing a blog on them at that time). We actually walked by #5 east side coming in and missed it, since it’s pretty overgrown now. I had several pictures that I’d not properly notated, so I probably got the numbering wrong. I appreciate the information and the warning. We were quite careful. These old grades can be tricky.