A guy that I used to work for grew up in UT somewhere near a ski resort. They used to call in the UT Nat'l Guard to use their artillery to start those avalanches for both the ski area and the highways. Worked great until one year when they had a couple NuuB's on the crew and a shell cleared the ridgeline barely missing some guy's barn a long ways away. Kind of put a hard stop to all of that.....
The climb going South out of Ouray, CO has paved places for the artillery and some propane fueled sonic cannons intended to promote the same thing, I think. Been a while since we were thru there.