Avalanche patterns

Avalanches are not indiscriminate killers; they typically bury young males, experienced snow users and people in big groups, recent studies show.

In the midst of a deadly avalanche season -- five skiers were killed near Park City, Utah, this month -- new research reveals a troubling pattern in accidents involving skiers, snowboarders and snowmobilers.

National Outdoor Leadership School instructor Ian McCammon has studied 662 avalanche cases in recent years and found:

* Some victims, such as the Utah skiers, ignore warnings, though many are trained in avalanche safety. Avalanche training appears to create overconfidence as snow users incurred more hazards than any other group.

* Nearly 70% of avalanche accidents occur on slopes familiar to victims, suggesting snow users overlook dangers on their favorite mountains.

* Skiers take more risks in pursuit of virgin powder.

* Most victims are male, in their late 20s and experienced in snow sports.

* Snow users in groups are more at risk than solo trekkers, suggesting individuals suspend caution when groups make decisions. People in groups with advanced avalanche training were almost twice as likely to get caught in avalanches as loners with similar training.

Charles Duhigg