Frank Slide, Landslide site in Crowsnest Pass, Canada

Frank Slide is a vast slope of angular grey and pale brown limestone rubble rising from large light grey boulders toward a barren ridge on Turtle Mountain. A finer apron of crushed rock fans down the middle, and small patches of green vegetation grow on the lower right edge.

On April 29, 1903, more than 82 million tons of limestone broke away from Turtle Mountain and buried part of the mining settlement of Frank under rubble. The slide lasted less than two minutes and killed at least 70 people, while some miners underground survived the collapse.

The Blackfoot and Kutenai peoples called Turtle Mountain "the mountain that moves" and refused to camp near it, a name that predates the 1903 slide. The Frank Slide Interpretive Centre, opened in 1985, presents this knowledge alongside the stories of the mining community. The site was designated a provincial historic resource in 1977.

Visitors can walk on marked trails through the boulder field and see the scale of the fallen rock mass up close. The interpretive center sits beside the main highway and offers guided walks from April through October along with information about geology and monitoring efforts.

Scientists monitor the south peak of Turtle Mountain with laser and radar technology because further rock movement remains possible. The instruments detect shifts as small as millimeters and send data to a monitoring system that can trigger warnings if needed.