An outstanding feat of engineering, the Spiral Tunnels in Yoho National Park were the ingenious early–20th-century solution to climbing or descending the impossibly steep 4.5-percent grade to cross Kicking Horse Pass by rail. Watch long freight trains cross themselves as they travel the tunnels in different directions at the same time.
It may take some patience, but you’ll be rewarded by the fascinating sight of freight trains (and the occasional passenger train) carving a figure eight through the mountains. It appears as though three trains are on the rails as parts of the train enter and exit the tunnels, giving the illusion they are moving separately.
See this fascinating example of brilliant railway engineering from either of two viewpoints—an upper and a lower—on a Banff National Park group day tour from Banff or Calgary, or as part of a self-driven tour.
Things to Know Before You Go
Train enthusiasts and history buffs won’t want to miss seeing the Spiral Tunnels in action.
Freight trains don’t follow a schedule, so be patient and be prepared to wait a bit to train-spot.
The lower viewpoint has a commemorative monument, information plaques, and restrooms. The upper viewpoint has no amenities.
Both viewpoints are accessible to wheelchairs and strollers.
How to Get There
The Lower Spiral Tunnel viewpoint is located on the Trans-Canada Highway (Hwy 1), 4.6 miles (7.4 kilometers) east of Field, British Columbia and 52 miles (84 kilometers) west of Banff, Alberta. There is also a pull-off viewpoint (of the Upper Spiral) on Yoho Valley Road, on the way to Takakkaw Falls from Field.
When to Get There
The lower tunnel viewpoint is open from mid-May until mid-October; the upper viewpoint (and access via Yoho Valley Road) is open from mid-June to mid-October. During the warmer months, trains run fairly frequently—up to every 15 minutes on some days—although they don’t follow a schedule.
CP Rail and the Big Hill
After the first rail attempt over Kicking Horse Pass ended in derailment and the tragic deaths of three railway workers in 1884, Canadian Pacific Railway devised the Big Hill solution. A series of switches allowed runaway trains a safe place to divert onto spur lines, not descending the grade until the train was under control. The introduction of the Spiral Tunnels in 1909 brought the grade to a much safer and more manageable 2 percent.