Avalanche Awareness for Snowmobilers
by Jim Frankenfield
Director, CSAC Avalanche Center
Preface - This is a version of a paper which was originally written
for Snowmobiling Online, which is online no more. Unfortunately I had
never saved a copy myself, but this version was printed in Rocky Mountain Powersport
News and they were kind enough to provide me with a copy of the correct back-issue.
Rocky Mountain Powersport News - Fall Edition 1997
This avalanche safety article is from the Cyberspace
Snow And Avalanche Center
For snowmobilers, exposure to avalanche hazards has increased rapidly in recent
years. High-power, lightweight machines with improved traction are enabling
snowmobilers to get into terrain that was once inaccessible by snowmobile. Consequently,
snowmobilers are having to re-think their attitudes toward avalanches and their
knowledge of avalanche safety.
Though it may seem like stating the obvious to say so, you can greatly reduce
your exposure to avalanche hazards by taking steps to avoid avalanches altogether.
Your first step should be to obtain general information about current snowpack
stability conditions in the area in which you plan to ride. Many regions
have an avalanche hotline you can call. Similar information is available online.
These bulletins are very educational - follow the bulletins for one area for
a season and you will learn a lot. If you are in the United States and the area
you sled in isn't covered by any official bulletin, try calling the local office
of the U.S. Forest Service. Many Forest Service offices employ a snow ranger
who can give you current information.
Mitigating the Risk
There are a number of steps you can take to minimize your risk. Even when conditions
seem quite stable, these simple precautions should be followed. In fact, they
should become a matter of habit.
Never expose more than one person at a time to a potential hazard. If
you must cross a hazardous slope, or cross below a hazardous slope, send
one snowmobiler at a time. The rest of the group should watch the person
exposed to the potential hazard until he or she is out of the danger area.
When sidehilling across a possible avalanche slope, cross it as high as
possible and have everyone in the group follow the same track. If you must
have more than one person cross a slope at the same time, spread out as
much as possible on the single track you all are following. Never have one
person above another.
One of the most common avalanche situations involving snowmobilers is highmarking,
the practice of competing to see who can climb highest on a slope. Never
have more than one person up on the slope at the same time! If somebody
gets stuck up on the slope, let him or her free the sled alone. If you go
up there to help, your added weight and the weight of your sled can introduce plenty
of stress to the snowpack. Often, that stress is sufficient to trigger a slide.
While the stuck snowmobiler is freeing his or her sled, where should the
rest of the group be? Well, not right down at the bottom, staring up at
the potential avalanche slope! Stay to one side or find a safe spot, but
keep an eye on the stuck snowmobiler.
Highmarking inherently involves being on steep slopes with potential avalanche
hazard, so if you are inclined to play this game often it would be a good
idea to learn more about stability analysis. Various field tests (such as
digging a quick snow pit) can help you determine the current stability before
highmarking on a particular slope.
Whether highmarking or not, consider your route carefully. Areas with trees
are generally safer than open slopes (although they are not always entirely
safe). The side of ridges facing the winds are typically scoured, hardpacked,
and safe, while the lee sides are often loaded with all the snow. Cornices
usually indicate that the slopes below are or have been loaded by the wind.
(Cornices themselves often break farther back than you might expect, so
give them wide berth.)