On my recent trip to Seattle, Washington, I visited the longest railroad tunnel in the U.S., the Cascade Tunnel, and checked out the action on the East Portal.
It is the longest railroad tunnel in the United States and was constructed by the Great Northern Railway, being put in service on January 12, 1929. The new tunnel reduced the summit by 501 feet (153 m) (to an altitude of 2,881 feet/878 metres) from the original tunnel, which had suffered problems with fumes, and was itself built to avoid problems caused by heavy winter snowfalls on the original line that had eight switchbacks
Dimensions
Total length: 41,200.0 ft. (7.8 mi.)
Also called
Great Northern Railway Cascade Tunnel #15
New Cascade Tunnel
Approximate latitude, longitude
+47.71532, -121.14522(decimal degrees) 47°42'55" N, 121°08'43" W (degrees°minutes'seconds")