Upper Spiral Tunnel Viewpoint

Upper Spiral Tunnel Viewpoint is a roadside pull-off 2.3 km up Yoho Valley Road, looking toward the active railway tunnel inside Cathedral Mountain. It is a short stop for a remarkable bit of railway engineering and the chance of seeing a train; the rail line can be hard to pick out through the trees. This is the upper tunnel viewpoint, separate from the lower spiral tunnel stop beside the Trans-Canada Highway.

Parks Canada counts an average of 25 to 30 trains through the Spiral Tunnels each day, but they do not keep a regular schedule. When one passes and the track is visible, its path through the mountain can make it appear at more than one height. Treat that as a lucky bonus, not something you can time. For a photo, keep the mountain and enough of the tree line in frame to show the train's route if it appears.

The Upper Spiral Tunnel runs 991 m through Cathedral Mountain and brings a train out 17 m higher. It was part of the solution to the steep Big Hill grade over Kicking Horse Pass, where the first train attempt in 1884 derailed and killed three workers. Safety spur lines were added for runaway trains while engineers worked on a better route.

Assistant chief engineer J.E. Schwitzer modeled the spiral solution on a system in Switzerland. The two tunnels were completed in 1909; after 25 years, the railway abandoned the old Big Hill grade. The loops made the pass safer and less steep, and the upper tunnel is the one cut through Cathedral Mountain.