Question: What year was the Cumberland Gap Tunnel, one of two mountain vehicular tunnels in the United States, opened which extended U.S. 58 from Harrogate, Tennessee to Virginia Beach, Virginia?
Sentence (from "Cumberland Gap Tunnel"): It is one of only two mountain vehicular tunnels in the United States that cross a state line, the other being the East River Mountain Tunnel on Interstate 77 between Virginia and West Virginia.
Relevant evidence: Yes