East River Mountain Tunnel

The East River Mountain Tunnel is a 5,412 ft vehicular tunnel that carries Interstate 77 (I-77) and U.S. Route 52 (US 52) through East River Mountain between Bluefield, West Virginia, and Rocky Gap, Virginia.

History
Construction began on August 12, 1969, and it opened on December 20, 1974. At a cost of $40 million (equivalent to $ in ), it was the most expensive construction project undertaken by the West Virginia Division of Highways at the time. The northern 51% of the tunnel is in West Virginia and the southern 49% in Virginia; Virginia shared the cost of the project.

Before the opening of the East River Mountain Tunnel, travelers wishing to cross the state line had to navigate the narrow, twisting, guardrail-less route of US 52 up and over the mountain (now designated as SR 598 and WV 598). When fog or snow was present, the journey became arduous, and the road was occasionally closed completely (particularly in the winter months) due to treacherous conditions.

Location
The tunnel is located about 20 mi north of its shorter cousin, the Big Walker Mountain Tunnel. The East River Mountain Tunnel is one of two land vehicular tunnels in the United States that cross a state line, the other being the Cumberland Gap Tunnel.

The top of East River Mountain can be seen in the distance from Big Walker Lookout, a 100 ft observation tower built on Big Walker Mountain.