The avalanche occurred Saturday at an informal snowmobile rally in British Columbia. Thirty people were injured, one critically.

The Royal Canadian Mounted Police say they believe the slide was triggered by a snowmobiling stunt known as high-marking, a contest to see who can race up the slope and leave the highest mark.

George Hall III of Browning, Montana, says he turned and wrapped his arms around his 13-year-old son in the seconds before the avalanche swept over them. Hall was knocked unconscious, but came to as rescuers dug him free. He had a gash on the back of his head. His son, George IV, says he saw stars floating in front of his eyes. The boy was banged up and bruised, but otherwise OK.

The older Hall says friend of his was killed. The man wasn't identified.