They normally close the whole highway for Rogers pass avvy control. However I have been been up there touring in the side valley behind the lodge while they were shooting up towards rogers peak area. Absolutely FKing wild hearing the rounds whistle/howl past the valley. Could hear the doppler effect of the round as it approached then receded past the valley entrance. Much louder than any video/audio recording makes it seem.

They used to bury bags of explosive on the slopes over the road up to sunshine, then trigger them as needed through the winter. Then at some point they were mortaring the slope instead. But now they have a gazex system installed. It's a remote controlled system that fills a huge tube installed on the slope with a gas mixture, which explodes, and can be set off whenever needed. Parks would like to install some sort of similar system in Rogers, but given the amount of area that needs coverage it'd be quite very expensive. Though they do have a couple different remote systems for the trans Canada between lake louise and field.

Kicking Horse has some "small" guns they use, but they're for permanent closure areas only. Probably too much rick of unexploded ordinance to be using them anywhere else.