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Avalanches

An avalanche is a large amount of snow moving quickly down a mountain, typically on slopes of 30 to 45 degrees. When an avalanche stops, the snow becomes solid like concrete and people are unable to dig out. People caught in avalanches can die from suffocation, trauma, or hypothermia. Avalanches can be caused by people, new snow, and wind. They move at speeds of 60 to 80 miles per hour. Peak avalanche season is December through March.

Know Your Avalanche Risk

Learn about your local avalanche risk. Know the signs of increased danger, including recent avalanches and shooting cracks across slopes. Avoid areas of increased risk, such as slopes steeper than 30 degrees or areas under steep slopes. Get training on how to recognize hazardous conditions and avalanche-prone locations. Sign up for alerts from a U.S. Forest Service Avalanche Center and Smart 911.

Preparing for Avalanche

Get proper equipment to protect yourself from head injuries and create air pockets. Receive first aid training so you can recognize and treat suffocation, hypothermia, traumatic injury and shock. Wear a helmet to help reduce head injuries and create air pockets. Wear an avalanche beacon to help rescuers locate you. Use an avalanche airbag that may help you from being completely buried. Carry a collapsible avalanche probe and a small shovel to help rescue others.

Signs of Avalanche

Learn the signs of an avalanche, and how to use safety and rescue equipment. Follow avalanche warnings on roads. Roads may be closed, or vehicles may be advised not to stop on the roadside.

The following are a few of the warning signs of unstable snow and possible avalanches:

  • You see an avalanche happen or see evidence of previous slides. 
  • Cracks form in the snow around your feet or skis. 
  • The ground feels hollow underfoot. 
  • You hear a “whumping” sound as you walk, which indicates that the snow is settling, and a slab might release. 
  • Heavy snowfall or rain in the past 24 hours 
  • Significant warming or rapidly increasing temperatures 
  • You see surface patterns on the snow made by the force of strong winds. This could indicate that snow has been transported and deposited in dangerous drifts that could release. 

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