Between 1924 and 1931, a narrow-gauge railroad hauled coal from the Crummies Creek mines to a prep plant on the other side of the mountain on Cemetery Road near Crummies, KY*. This portal, probably dynamited and then filled in, is near 36.78559, -83.21749. Good luck trying to find it on Google Earth. We nearly missed it ourselves. When I took this picture, I was standing on top of the fill looking into the tunnel right at the top. I could feel cool air blowing out, so the tunnel’s not completely filled in.
On the prep plant side, there were several L&N lines that used a double-track loader. The tracks are gone now.
*The Kentucky place name list tells me that a “crummy” or “crummie” refers to an animal that has crooked horns.
Blogging the Railroad Tunnels 
If your coordinates are correct here I think this would be the tram tunnel for the old Mill Ridge Coal Company. They operated two mines, one in the Harlan seam and another in the higher Darby. The tunnel shows up on older Topo maps. Look to the right (east) of Cawood and the left (west) of Slack Hollow on an “Evarts” topo map. This operation went in during late 1947 and the tramway would have served their Darby mine. Crummies Creek Coal Company didn’t operate any mines in reserves north of Long Branch and west of Slack Hollow. That area was all controlled by Alabama Fuel & Iron Company while Crummies operated on leases from Hall Land & Mining.
Great find! Really amazing no one has stripped that ridge and obliterated this relic yet.
Thank you for your informative comment!