By: Marlene Affeld
Montana - “The Last Best Place” is a land of contrasts. We are blessed with high mountain ranges and deep fertile valleys, singing mountain brooks and raging rivers. The weather is, however, one of our biggest contrasts.
Our seasons are dramatic. Gentle green days of spring, blazing heat of a summer sun, crisp clear days of autumn and then the cold. The gray days of sub-zero temperatures are our greatest challenge.
Winter storms are the most life-threatening of any natural hazard Montanans face. Accurate statistics on winter related deaths are hard to tally, however Montana has one of the highest cold weather related death counts in the nation.
Numerous people succumb to hypothermia due to extended exposure to the cold, traffic accidents on icy, snow covered roads, heart attacks from overexertion and avalanche activity. Most residents of Montana prepare for winter. We celebrate winter. Montana is a sportsman’s paradise and for those who can’t wait to go snowmobiling, skiing or ice fishing, winter is an anticipated event. We know the snow is coming, the wind will blow and temperatures will plummet. It’s just a matter of how cold it will get and how much snow will accumulate.
In preparation for winter, supplies are laid in, firewood cut and equipment and vehicles winterized. Old Man Winter, bring it on! We are ready! Or so we would like to think.
Life threatening problems tend to develop during record snowfalls or during periods of deep cold. During a heavy, rapid snowfall the snow plows and sand trucks are overwhelmed and most roads become impassable. Ice storms or heavy wet snow brings down trees and power lines, roofs collapse under the snow load and water pipes freeze. Prolonged frigid temperatures, especially when accompanied by fierce, bitter winds, create dangerous situations for people stranded outdoors or those without heat, as when the power lines are down or the propane truck can’t navigate the roads. Due to the remote locations where power lines often go down, power outages of several days are not uncommon.
Avalanches are significant hazards . Avalanches happen in a split second, advancing with the force and speed of a freight train and can often pose a serious threat to winter travelers and recreational users of the back country. It is impossible for a skier or snowmobiler to outrun an avalanche. An avalanche can move at speeds up to 200 miles an hour.
There are two types of avalanches. A loose snow avalanche starts over a small area and grows in size as it crashes down the mountain face. Slab avalanches begin when a large mass of snow begins to slide at once. There will be a clearly marked fracture line where the snow mass breaks away. Slab avalanches are the most dangerous as they often contain boulders and huge blocks of snow and ice. Slab avalanches are a threat to snowmobilers and skiers. Unfortunately slab avalanches are most often triggered by the victims themselves.
The State of Montana Multi-Hazard Mitigation Plan and Statewide Hazard Assessment - October 2004, describes an avalanche:
“A mass of loosened snow, ice, and/or earth suddenly and swiftly sliding down a mountain. In practice, assumed to be a snow avalanche unless another term such as ice, rock, mud, etc is used. Synonymous with "snow slide".
Avalanches occur throughout the mountains of Montana and, to a limited extent, elsewhere in the state. Avalanche hazards most directly threaten winter recreationists, homes and businesses in mountainous regions, and communication and transportation networks. Two of Montana’s ski areas, Bridger Bowl and Big Sky, are respectively the second and fourth most avalanche-prone ski resorts in the entire United States.
Of the major avalanche hazards, the interruption of communications lines probably occurs most frequently. Places of highest hazard include ski areas, mountain passes and other areas where transmission lines cross avalanche paths. In regions where important highways or railroads cross areas subject to frequent snow slides, losses resulting from blocked roads, buried railroad tracks and destroyed bridges can reach into the millions of dollars.
The complex interaction of weather and terrain factors contributes to the location, size and timing of avalanches. In the absence of detailed scientific observation, any accumulation of snow on a slope steeper than 20 degrees should be considered a potential avalanche hazard.
The most certain sign of avalanche hazard is avalanche activity. Usually when one slope is hazardous, many of the nearby slopes are also hazardous. The historical record shows numerous cases where rescue parties searching for avalanche victims themselves become victims of the same avalanche cycle.
Knowledge and experience save lives. If you are ever caught in an avalanche there are some important things to try to remember:
1. Immediately call out. If you have an emergency whistle, use it.
2. If you are snowmobiling, discard all equipment and move away from your snowmobile.
3. Make swimming motions.
4. Attempt to stay on top of the snow flow and work your way to the side.
5. Before you come to a stop, put your hands in front of your face and try to make an air pocket.
6. Remain calm to conserve oxygen.