deepest tunnel

How Long Is The Moffat Tunnel? Overview Length6.2 miles (10.0 km) Track gauge 4 ft 81⁄2 in (1,435 mm) standard gauge Highest elevation 9,239 feet (2,816 m) above sea level Tunnel clearance 24 feet (7.3 m) What is the longest train tunnel in the United States? Cascade Tunnel, the longest railroad tunnel in the United