18+ Longest Mountain Tunnel In Us Pics. Delaware aqueduct is the longest tunnel in the world at 85 miles long and 13.5 feet wide. The longest road tunnel in north america is the anton anderson memorial tunnel in alaska, at 2.5 miles.
The longest tunnel in montana has a truly fascinating backstory if you've ever ridden amtrak's empire builder, you've probably passed through the flathead tunnel.
It was constructed between 1939 and 1945 and supplies water from rondout reservoir to the chelsea pump station before ending at hillview reservoir in yonkers. That tunnel was 2,966 feet. With a maximum elevation of 11,158 ft (3401 m) above sea level, it is one of the world's highest road tunnels and the longest mountain tunnel. Delaware aqueduct is the longest tunnel in the world at 85 miles long and 13.5 feet wide.