Frank Slide!

This is the Frank Slide, which occurred on

April 29, 1903. Basically a mountainside of rock gave way just east of Crowsnest Pass, near the Continental Divide in SW Alberta. In about 90 seconds, 30 MILLION cubic meters of rock roared down the mountainside, across the valley below, and well up the slope on the other side of the valley, where this picture was taken. 70 people were killed; a mile of railroad track was obliterated. Imagine the force of the rock! It was estimated to be moving at 75 mph. In all, the debris from the rockslide covered about a square mile. It was determined that, in addition to natural causes, the widespread coal mining in the immediate vicinity also probably played a part in destabilizing the mountainside.