Watch some of the megavalanche videos on youtube. Besides being extremely awesome they also start off on the top of a mountain in snow in a huge pack and wreck a lot while running into each other constantly.

https://www.youtube.com/watch?v=XxY9dMq5BjI
The amateurs class is a good example of that since they spend more time sliding down the mountain than riding down it lol. Check out one of the full runs by a pro too if you have an hour to kill, very cool.