This tunnel, referred to in early N&W documents as “Tunnel 377”, was first known as the Coaldale tunnel, but is now officially (as the sign on the lintel says) the Elkhorn tunnel.  Shown is the SE portal at 37.333022, -81.338904, about one mile as the crow flies, from the NW portal of the Coopers tunnel, across the Bluestone River.  The tunnel is on the Flat Top Extension, which opened up a way to the Ohio River for the N&W.  It was excavated between 1887-1888 and is 1.3 miles long.

 

 

 

 

As you can tell by the comment below, this posting is pretty much just twaddle.  This is the Elkhorn Tunnel, but it’s Elkhorn Tunnel #2. The original tunnel was a single-track jobbie about 3,100′ long.  That line was electrified between about 1915 to just after WWII.  Wanting double tracks and seeing needs shift, N&W bored this tunnel, about 1.5 miles NW from Bramwell WV.  It was dedicated in 1950.
According to Buddy French (http://shinbrierwv.com/coaldale/return_to_coaldale_-_great_story_by_buddy_french), the old Elkhorn Tunnel, located at Coaldale, was abandoned and filled in after the new line was built.

I always appreciate comments and corrections, always!