****Before the slide*** _______________________________________________________________***After the slide***


If you do not already consider one of your primary life goals safety it had better become important when you venture into backcountry skiing and avalanche terrain. The two are virtually synonymous. Avalanches have a tendency to clear out the forest and fill in with snow and do it again. And the alpine is the starting zone often below the wind drifted ridge. Bruce Tremper boils it down quite well when he equates that 95% percent of the time the snow on avalanche terrain is stable, if you ski 100 days in avalanche terrain and mind not the random stability you will get slid, launched, swept away into the cheese grater river of snow five times. If you have never been in this river swimming you can only imagine the power, more like concrete slurry in the end. Imagine swimming down a steep, mountain slope in a current of cold concrete and you get the idea.

So that is what we are trying to avoid when talking avalanches: starting a slide on a slope we can safely ski otherwise or avoid entirely. Avalanche slopes have an angle that is conducive to skiing. Every time you turn on a slope it shocks the snowpack which may cause a slide to start. The slope angle professionals tell us that the mean of the bell curve for avalanche accidents is 38 degrees: wear that inclinometer around your neck and measure your slope angles, it may save your life…seriously. Below 35 degrees avalanches become less frequent as they do above 45 degrees. Below 30 degrees they are quite rare as starting zones but will slide from a release above very readily.

So if you pay micro attention to the slope angles that you ski, you will reduce the risk of stepping on a trigger and going down the hill in an avalanche. Triggers can be slow to find in some cases. Hence there is a set of golden rules to skling avalanche terrain. First has got to be wearing a beacon, avalung and helmet for your self protection, and carrying a shovel and probe in your pack. Secondly in avalanche terrain spread out the group. Obviously more weight is more likely to trigger slides. Spread out the group on both uptrack and while skiing. This makes groups of 2-4 ideal. With good safety coverage and not too many to induce bunching, three to four in a group can cycle through breaking trail chores and trade off skiing runs first or last with the best efficiency and safety.

Secondly expose only one person at a time to avalanche terrain or if that is totallyt impractical due to the length or size of the feature being crossed or skied spread out as much as possible, this might mean ten minutes on the uptrack and giving each other three or more full minutes on the descent. Use your watch to measure time as we are all excited to hit the powder. A third rule is to operate from a position of safety. Before dropping into the avalanche zone, and while waiting for your partner to ski, it is imperative that you are in a safe location preferably, but secondarily with a view of the skiers on the run. Likewise when you finish skiing through avalanche terrain move away to the sides, onto a hillock, or into the trees so that you are no longer exposed to a slide from above. Keep your skis pointed in the direction of further safety in case you need to move quickly. Only through constant diligence towards recognizing exposure to avalanche threats can we reduce the chances of being slid, buried, and not having a partner capable of rescue. Be aware when you are breaking the rules and make others in your party aware as well. Remember this is your and your partners' lives at stake and there should be no powder frenzy like at the ski area. Other rules while skiing into avalanche terrain include being aware of escape routes, stack tracks or figure eight if possible, and ski the fallline. Try to avoid falling especially during more considerable avalanche hazard when you know the snowpack is touchy and reactive. Ski with at least one partner whenever possible; take considerably less risk when alone. There is always the option of avoiding avalance terrain altogether.

Trigger points are an important part of realizing safety in avalanche terrain. Steep rollovers, convex slopes, rock islands, and steep headwall entries, and wind loading areas are all potential trigger spots. Be constantly on the lookout for them. Pay close attention to crossloaded spots that build up isolated heavy bulges that are not anchored well below or on the sides. Know when you step from safe terrain to hazardous terrain as it is always a matter of just a few feet. Trigger points are very important as we well know the cases where many skiers have hit a run before it releases. Use this knowledge to judge your line, they are all a bit different. Be careful during wind events as slopes can quickly become a considerable hazard that were moderate before the wind.

Trees can afford a good margin of safety if they are on a slope between 25-35 degrees. Above 35 do not expect the trees to do much to inhibit a slide if the snow is unstable. Furthermore trees are very dangerous when you are caught in a slide. They will break you up and kill you quicker than all else save cliffs and gully features. When skiing avalanche terrain it is very important not only to assess the slope's steepness and hazard at that time but what is the survivability of being caught in a slide. If the run is a big, concave run with a long low angled runout with no trees and rocks or cliff bands then if you are slid you have a much higher probability of escaping death or serious trauma then if the slope has trees, rocks, cliffs or an abrupt gully or flat ending. Think about all these things before commiting to avalanche terrain.

Warning signs that the snowpack is unsafe or of marginal safety include whumpfing of the snow on any steepness. This is the upper snowpack collapsing a weak layer(s) and settling. This often happens in early season but can be experienced at any time of season. Shooting cracks from your skis is another obvious sign of instability. Natural avalanches show that snow stabilty is quite bad. Knowing there is buried surface hoar is another sure indicator of instability. This fact makes touring before the next storm and getting an idea of local surface hoar production a very good idea. Surface hoar grows as plate-like and feather-like crystals on the surface of the snowpack during clear nights. It is obvious to see when advanced and less so during the first day of production. Assuming there is some on sheltered terrain if you have had clear nights is reasonable. Wind and sun are good surface hoar busters. If your latest storm came in with little wind preceeding it, then assume that you have some surface hoar underneath especially on shaded aspects. When breaking fresh trail observe the way the snow breaks up between your skis and when making switchbacks. If it is blocky and cracks when turning then you know that stability is not great. Don't let any clues go unnoticed. When snow is settling and falling from trees this is a good sign that the snow is settling, not that it is safe. Steeper slopes may have evidence of regular sloughing. This is a good thing as it means the snow is regularly equalizing and sliding to reach stasis. This regular sloughing encourages settling and stabilizing.

Snowpits: ******Movie*****


Digging into the snowpack to determine stability has become a necessity for the backcountry traveler. If you want to play and do it safely digging pits right next to your line will give you the best look at the stability there. Of course the pit digger needs to know what to look for in the snow profile 6 feet deep. What causes most avalanches is a bed surface failure, otherwise known as a collapse of the weakest layer affected by your skis and weight. The layer loses all its bonds in a brief few moments, and then the slab on top is free to slide if the stauchwall at the bottom allows the slab to pop out of the snow and start ripping down the mountain with an ever increasing velocity depending on the slope length. Long avalanche paths aka great ski runs can produce large avalanche, small slopes can produce smaller but equally dangerous slides to the skier.

Use test slopes to get a feel for stability. Small steep sections along the trail and during the day can tell you a bit about the stability of larger more deadly slopes. Never use just one isolated stability test to determine your go or no go decision for a slope on a tour. Spend the time to gather evidence the whole day to your objective and remember that saying no will save your life.

Snow pit evaluation tests:

Shovel Shear test- identifies shear layers in the pit

Compression test-identifies how much compression is necessary to create failure at various layers. Stuffblock and Shovel Tap

Rutschblock Test- similar to the compression test with a full size column isoltae and a skier used as the compression force.

Tilt test- A test to isolate weaknesses in the upper 18 inches of snow.

Generally avalanches start to slide on open and open treed slopes. If you can ski downhill through the glade it is open enough to slide, look for branches missing to determine slide history. So your lane is open enough to ski and steep enough to be exciting; voila avalanche country. No wonder the number of deaths has been steadily increasing amongst skiers, boarders and snow mobiles, it is really fun to play where the avalanche dragon lies. There are really good books about avalanche awareness and learning more detail about avoiding them.

Golden rules to reduce risk in avalanche terrain:
-Spread out the party on the uptrack
-Ski one at a time while in avalanche terrain with 3 minute rule.
-Wear a tested beacon and have experience using it. Wear a helmet and avalung.
-Carry a shovel, and a probe, in a pack with emergency gear
-Wait in safety zones and communicate effectively with your partners
-Do not ski avalanche terrain when danger rating is considerable or higher
-Dig a series of snow profile pits throughout the season to learn about snow

Safety is a constant group and personal dialogue where we must continually monitor ourselves as much as the conditions. Pay attention to your instincts. While you are inexperienced it is good if you usually feel nervous in avalanche terrain. Only through years of studying regularly avalanche danger signs will you truly begin feeling somewhat comfortable in avalanche terrain; otherwise you will be best served by being scared and cautious.

The most rewarding aspect to a tour is having spent a safe and exciting day in the mountains and heading home or to the tent to a good meal and sleeping comfortably with those you love safe around. Skiing avalanche terrain is often very scary at first and dealing with this fear factor as well as the excitement factor is every bit as challenging as analyzing the snowpack for signs of instability. Dealing with your ego is every bit as important as determining a sense of snow stability.

If avalanche terrain is safe for travel 95% of the time, what are the conditions that produce slides. As may be obvious heavy snowfall and winddrifting of snow are the most obvious factors in producing instability. Beware of snowstorms and high winds at ridge tops and across snowfields.

The other major factor increasing snow instability is rapid warming. This most frequently occurs through two factors solar gain and rain. Heavy rain may be the most dangerous sign of impending doom, fortunately it is not a desirable time to ski as well.
But while the storm rolls in and blankets your favorite lines with a fresh icing and the cold powder sits there waiting for your tracks it is also adjusting to itself and the snow it landed upon. These conditions can be the best deep powder days of your life, like never truly known at the ski area . With snow blowing up around your chest and neck and frosting your nose and view, deep powder is a unique substance to ski. After a day or three new snow will be more settled compared to fresh snow, making multiple day snowstorms a must for the fat skis on moderate angled terrain.

In snow science the professionals have identified a number of lemons that seem to recur in the avalanches that get people and that the pros monitor.
These lemons include:
-a weak layers in the top meter of snow,
-a thin weak layer, more than a single step in hardness difference between
adjacent layers,
- the prescence of near surface recrystalized snow (facets).

So now we have the basics of knowing avalanche terrain, knowing avalanche weather, and how to avoid being avalanched. Experience is the key and instead of writing anymore on it, get some more experience, and read some of the great books available with a click of the mouse. In Montana check Chapter One Bookstore in Hamilton they will order for you. In a few days only you will have the book.

Staying Alive In Avalanche Terrain Bruce Tremper
Avalanche Safety for Climbers and Skiers Tony Daffern
The ABCs of Avalanche Safety Dick LaChapelle

Further Online Resources:

Gallatin Nat'l Forest Tutorials Links

Gallatin Nat'l Forest Videos

Utah Avalanche Center Tutorial

Utah Center You Tube Channel

Surviving an Avalanche Strategies


Backcountry skiing and travel in the wild mountains is a potentially dangerous sport. Hazards range from trees, rocks, ice, avalanches, stream crossings, lake crossings, wind, blizzards, sunshine, cold, to snowmachines, ego, over exertion, hunters, mountain lions, bears, wolverines, wolves, and other skiers. The publisher and editor encourage all backcountry users to have sufficient skills, knowledge, and judgement in their use of the infomation in this website. Using the information herein is solely at the discretion of and is the responsibility of the user/reader and we expect all to understand the inherent risks in following any of the tour descriptions found on these pages. Different snow years will produce differing conditions, and of course different times of year and day will alter conditions as well. Most of the tours in this website are subject to skier triggered avalanches. Beware of these conditions. There may be errors in the descriptions and you may have trouble finding the exact locations described. Use good judgement and communication. Rely on yourself and your party for this judgement and also for self rescue. Know when to turn back; leave the ego for book reading and time spent with family. -eds