The Canadian Pacific Railroad runs over Kicking Horse Pass between British Columbia and Alberta. Two spiral tunnels were built to reduce the grade from 4.5% to 2.2%. In this photo, you can see the back end of the train entering one of the tunnels at point 1, while the front of the train is already emerging from the same tunnel at point 2, 51' below the cars above it. Read more about this on the Internet--search for "CP Rail Spiral Tunnel."
