Avalanches

Avalanches Kill

Since 1950, 176 climbers have been buried and killed by avalanches in the United States (Climbing.com and Avalanche.org). When the first edition of the book was published in 1980, and even when the second edition was published in 1990, winter climbing was not popular in Idaho. But in the last 15 years, winter ascents and skiing/snowboarding Idaho’s backcountry peaks have become increasingly popular.

As of 2018, most of the 41 Idaho avalanche fatalities were snowmobilers, followed by skiers and snowboarders. However in 1977, two climbers from Idaho, Vaughn Howard and Guy Campbell, died when they triggered an avalanche on Mount Borah’s Northwest Ridge route. In 1987, David Probst died in a rare combination of events involving an avalanche on Mount Borah, and in 2005, Jarad Speers died when he triggered an avalanche while snowboarding after summiting Castle Peak.

Most avalanches occur in winter, particularly from December to April, though avalanches involving climbers occasionally happen in the summer months. However, avalanches can, and do, occur anytime conditions are right.

Avalanche path. Larry Prescott Photo

Winter climbing is more dangerous than during dry conditions because of cold and avalanche danger. Most routes in the book and on this website are not recommended in winter because of increased hazards related to winter conditions.

The National Weather Service (NWS) discussion of avalanche dangers is instructive, it states:

An avalanche is a rapid flow of snow down a hill or mountainside. Although avalanches can occur on any steep slope given the right conditions, certain times of the year and types of locations are naturally more dangerous. While avalanches are sudden, there are typically a number of warning signs you can look for or feel before one occurs. In 90 percent of avalanche incidents, the snow slides are triggered by the victim or someone in the victim’s party. Avalanches kill more than 150 people worldwide each year. The National Weather Service provides current weather conditions and forecast information to regional avalanche forecast centers that in-turn issue avalanche forecasts. Avalanche warnings and special advisories are included on NWS websites and broadcast over NOAA Weather Radio. Refer to your local avalanche center for current snowpack conditions!

How to Stay Safe

The NWS also provides the following information on how to stay safe.

Get Training

Avalanche.org provides introductory online training and can direct you to a hands-on class in your area.

Know the Factors Required for an Avalanche

  • Slope: Avalanches generally occur on slopes steeper than 30 degrees. Determine if you are on or below slopes that can avalanche.
  • Snowpack Volume and Stability: Recent avalanches, shooting cracks, and “whumping” sounds are signs of unstable snow. Find out if the snow is stable, know how to dig a test pit and interpret what the pit shows you.
  • Trigger: It doesn’t take much to tip the balance. People, new snow, and wind are common triggers.

Get the Advisory

Refer to your local avalanche center for current snowpack conditions!

Get the Gear

Have the appropriate gear, learn how to use it, and practice so you are great at it! Have these three avalanche safety essentials in your pack:

  • Transceiver: So rescuers can find you if covered by the snow
  • Shovel: So you can dig out your partner
  • Probe: So you can locate someone who has been covered by the snow

Avalanche survival rates plummet after about 15 minutes for victims who do not die from trauma. Saving your partner is up to you! Practicing realistic scenarios beforehand is essential.

Avalanche Warning Signs

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 has occurred in the past 24 hours
  • Temperatures have significantly warmed or are rapidly increasing
  • You see surface patterns on the snow made by the force of strong winds, indicating snow may be deposited in dangerous drifts that can release.

For additional information read the NWS brochure at this link: Avalanches

Take the time to learn about avalanches from a professional. Find the avalanche center covering the area of your interest, and heed all warnings.i