Historic railroad tunnel under Continental Divide about 50 miles west of Denver. Was among the longest in the world when completed in 1928, is today third longest railroad tunnel in the United States. Digging it was difficult, due to fractured bedrock and underground aquifers. The first train went through the tunnel in February 1928. In 1979, the tunnel was designated a National Historic Civil Engineering Landmark. Heavily used today for both freight and passenger trains, especially after the closing of the more challenging Tennessee Pass line in 1997. You can visit both portals, and you can ride through it on the Amtrak California Zephyr and Winter Park Express passenger trains.
The tunnel was built by the Moffat Tunnel Improvement District, an independent entity of the State of Colorado. The district was dissolved in 1998, and its assets, including the tunnel, passed directly to the state. The Union Pacific Railroad holds a lease until 2025.
After completion of the railroad tunnel, the pilot bore was converted to carry water from the Western Slope to Denver. This water tunnel was sold to the City of Denver when the district was dissolved in 1998.
Tunnel under Continental Divide west of Denver on Union Pacific RR