As people migrated across the United States to settle the new frontier, the Rocky Mountains were a formidable obstacle in getting to the West Coast. David Moffat, a railroad pioneer at the turn of the century, mapped out a new route over Colorado’s Continental Divide between Denver and Salt Lake City.
The current rail passage consisted of steep 4% grades and switch backs over Rollins Pass. Additional engines were added to trains to pull them over the pass, and clearing the snow from the tracks in the winter was an unprofitable task. Railroads connecting the Rocky Mountains to the West Coast were already in place from Cheyenne, Wyoming and to the South out of Pueblo.
Moffat’s plan competed with the other lines and connected Denver with Salt Lake City, which included a 6 mile tunnel through the Continental Divide. The new route and tunnel would shorten the distance from Denver to Salt Lake City by 23 miles and reduce the grade by a full 2%. Trains going to Salt Lake from Denver using the route through Pueblo would add an additional 154 miles.
Moffat worked to get funding for the project, but was hampered by political roadblocks. At the time, Pueblo was an economic rival to Denver and there was political pressure to keep Pueblo as the preferred route to the west. But in 1922, severe flooding in Pueblo, delaying train passage, created the political advantage proponents needed. Legislation was then passed to issue bonds for the construction of the new line and tunnel.
Construction of the tunnel began in 1923. David Moffat would not live to see the completion of the tunnel in 1927 and first train passage in 1928. The fourth longest railroad tunnel in North America would be named in his honor. Construction of the tunnel took five years at a final cost of $15.6 million and the loss of 28 lives. The project excavated 6 billion pounds of rock.
In addition to the 24 foot high main tunnel, an initial pilot bore tunnel was constructed in parallel 75 feet away. The eight foot wide tunnel was enlarged to 10-½ feet, and beginning in 1936, used to carry water diverted from the western side of the Continental Divide to the Front Range.
Water coming through the Moffat tunnel actually goes through a series or other man-made tunnels, crossing the Continental Divide three times. In 1979 the water tunnel was sold by the Moffat Tunnel Improvement District to the city of Denver where it continues to provide water to Englewood and the Denver metro area today.