Just west of the Canadian Rockies’ Continental Divide lies Yoho National Park, a beautiful land of jagged peaks and roaring rivers. Back in the late 19th century, however, the Canadian Pacific Railway company didn’t exactly see the beauty of Yoho. After all, the company had to figure out a way across the notorious Kicking Horse Pass and its perilous 1,000-foot drop from Wapta Lake to the plains just east of Field. Determining how to safely create one of the steepest railroad stretches in the world was no easy task. The original rail route had a dangerous 4 percent gradient, and it was a disaster. The first train crashed straight into a canyon, and it would be another 25 years before the CPR would build Spiral Tunnels.
Spiral Tunnels was completed in 1909 and remains a true feat of engineering: two vast tunnels running figure-eight loops through the snowcapped mountains. The upper tunnel cuts a swath through Cathedral Mountain for 1,000 yards, while the lower tunnel steers through Mt Ogden. By going around in loops, Spiral Tunnels double the length of this railroad stretch, reducing the gradient to a much safer 2 percent.
Watching two-mile-long freight trains rush through Spiral Tunnels is quite a sight. It takes a while to realize you’re not watching three different trains going in opposite directions, but instead, one long train looping over and under itself, deep into the mountains and up the valley to the Kicking Horse Pass.
Trains can run through the tunnels every 15 minutes or so in the summer, though be prepared to wait. There are many information plaques at the Lower Spiral Tunnel Viewpoint, five miles east of the town of Field in British Columbia and more information about Spiral Tunnels at the visitor center in town.