Avalanches are a serious risk

The spate of avalanches (snowslides) that have closed Highway 20 several times in the last several weeks are a perfect example of the winter hazards that are a deadly threat to skiers, snowboarders and snowmobilers in our area.

Avalanches occur only on slopes steeper than about 25 degrees, and they most often occur on slopes between about 35 and 45 degrees. Learning to recognize avalanche terrain is the first step in keeping yourself safe in the back country.

The steepness of a slope, its orientation (the direction it faces), the shape of the slope and its natural features are all important in determining whether a slope can slide. Of these factors, the steepness of the slope is the most important in recognizing risks.

However, staying off steep slopes is not a guarantee of safety in avalanche country. All of the snow is connected, and traveling on a flat slope or snow-covered road can also be hazardous. If the snowpack is unstable enough, a slide may be triggered on a steeper slope above you.

Some avalanche paths are relatively easy to spot; however, nearly half of all winter accidents involving avalanches occur on slopes that are less than 300 feet long and that are not obvious to the untrained.

There are two ways to approach winter fun in the back country. One is to avoid avalanche terrain altogether; the other is to learn how to recognize and assess avalanche danger.

Several groups offer avalanche training in Oregon. Closest to Sisters are Central Oregon Community College, which offers safety classes and the University of Oregon in Eugene, which has an outdoor pursuits program (www.uoregon.edu/~opp/). Another program is available through the Mountain Savvy course held at Mount Hood (www.mountainsavvy.com).

Excellent free information is additionally available online through the non-profit Colorado-based organization called Avalanche (www.avalanche.org). This organization works with the U.S. Forest Service and other international organizations to provide education and information resources on the winter hazard of avalanches both in the United States and abroad.