This tunnel unites Kermit and Speers Ferry VA in Scott County west of Gate City (see comment below). The tunnel is over 4,000′ long. This string is heading north. Just behind me and to the right is a curve that creates banshee-like shrieks as the wheels negotiate it (how do trains, without a differential, as such, handle curves? Read here.)
Blogging the Railroad Tunnels 
Correction on the state connection. This tunnel goes from Speers Ferry VA to Kermit VA. It is quite a few more miles before the track reaches TN.
You’re absolutely correct. I cannot explain why I thought Kermit was in Tennessee. Thank you for the comment.