Tree Well Safety
SIS stands for Snow Immersion Death. SIS incidents occur with deep snow or tree well immersions, in which a rider or skier falls into an area of deep, unconsolidated snow and becomes immobilized. The more the person struggles, the more entrapped in the snow they become, risking suffocation.
• Always ski and ride with a partner. To minimize your risk, you must know how to travel safely with your partners in ungroomed deep snow areas.
• Always stay in visual contact so your partner(s) can see you if you fall. Visual contact means stopping and watching your partner descend at all times and proceeding downhill while he or she watches you at all times. It does no good if your partner is already waiting for you in the lift line while you are still descending the slope.
• Stay close enough to either pull or dig out. If you have any question about what "close enough" to assist someone in a tree well is, hold your breath while you are reading this. The amount of time before you need air may be how much time your partner has to pull or dig you out of danger. Other factors such as creating an air pocket or the position you fall in may affect this critical timeframe.
• Remember, don't lose visual contact with your partner, or you could lose your friend. It is important to know that most people who have died in deep snow or tree well accidents had been skiing or riding with partners at the time of their accidents. Unfortunately, none of these partners were in visual contact, so they were not able to help in time.
If you have additional questions, please contact Jackson Hole Mountain Resort Ski Patrol.