The Nada Tunnel is located along Kentucky Route 77 in Clay County, Kentucky, and is one of the best ways to enter the Red River Gorge Geological Area in the Daniel Boone National Forest. The 900-foot, one-lane tunnel was constructed from December 1910 to September 1911 for the Big Woods, Red River and Lombard narrow gauge railroad, and measured 13-feet wide by 12-feet tall. Only one fatality was recorded during its construction when a construction worker attempted to thaw frozen dynamite by setting it near a fire.
A 25-ton and a 35-ton Climax locomotive was used to haul logs from the Red River valley through the tunnel to a saw mill 15 miles west in Clay City. The first load of logs, however, became jammed in the tunnel and had to be dynamited loose. The Nada Tunnel was then enlarged to accommodate larger loads.
The Nada Tunnel is listed National Register of Historic Places.
- Designation: KY 77
- Total Length: 900 feet
- Height (Vertical Clearance): 12 ft.
- Width: 13 ft.
- Number of Lanes: 1