Quick answer: check the local avalanche forecast before every trip, stay off and away from slopes steeper than about 30 degrees when danger is elevated, and camp well outside avalanche paths and runout zones. If your route crosses avalanche terrain, every person needs a transceiver, probe and shovel, and the training to use them. Taking a recognized avalanche course is the best single step you can take.
Snow-covered mountains are some of the most beautiful places to camp, and they come with a hazard that summer campers never face: avalanches. Many winter campers stay in gentle, low-angle terrain where avalanches are not a concern. But trails, roads and campsites in the mountains can pass below or across steep slopes, and a slope does not have to be huge to bury a person.
This guide is part of our complete winter camping guide. It is an introduction to avalanche awareness, not a substitute for formal training. It covers the forecast and danger scale, avalanche terrain, campsite selection, essential rescue gear and where to learn more.
Sources: Avalanche.org and the U.S. avalanche center network (including the North American Public Avalanche Danger Scale and avalanche problem types); American Avalanche Association; American Institute for Avalanche Research and Education (AIARE) course descriptions; Avalanche Canada public education materials; U.S. Forest Service avalanche center information.
How Avalanches Happen
An avalanche is a mass of snow sliding down a slope. The type most responsible for deaths among backcountry travelers is the slab avalanche, in which a cohesive layer of snow breaks away from a weaker layer below it and slides as a block before breaking up. Slab avalanches can be triggered by the weight of a single person on skis, a snowshoer or a snowmobile.
Avalanche centers note that in most fatal avalanches, the victim or someone in their party triggered the slide. That is sobering, but it also means that decisions about where and when to travel make a big difference.
Three ingredients are needed for an avalanche:
- A slope steep enough to slide. Most slab avalanches release on slopes between about 30 and 45 degrees.
- An unstable snowpack. Weak layers, new snow, wind-loaded snow or rapid warming can make the snowpack unstable.
- A trigger. Natural triggers include new snow, wind and warming. Human triggers include people walking, skiing, snowshoeing or riding.
You cannot control the snowpack, but you can control whether you put yourself on or under steep slopes when the snowpack is unstable.
Read the Avalanche Forecast Before Every Trip
Many mountain regions in the United States and Canada have avalanche centers that publish forecasts during the winter. In the United States, Avalanche.org links to regional avalanche centers, many of which are run by or partnered with the U.S. Forest Service. In Canada, Avalanche Canada provides forecasts for many regions.
A forecast usually includes:
- The danger rating for different elevation bands.
- Avalanche problems, such as wind slabs, storm slabs, persistent slabs, wet snow or cornices, with information about where they are found and how likely and large avalanches may be.
- A summary of recent weather, observations and travel advice.
Read the whole forecast, not just the color. The avalanche problems tell you which slopes and aspects are most dangerous on a given day.
The North American Public Avalanche Danger Scale
Forecasts in the United States and Canada use a five-level scale:
| Level | Name | General meaning |
|---|---|---|
| 1 | Low | Generally safe avalanche conditions; watch for unstable snow on isolated terrain features |
| 2 | Moderate | Heightened avalanche conditions on specific terrain features |
| 3 | Considerable | Dangerous avalanche conditions; careful snowpack evaluation and conservative decisions are essential |
| 4 | High | Very dangerous avalanche conditions; travel in avalanche terrain is not recommended |
| 5 | Extreme | Avoid all avalanche terrain |
Avalanche centers note that many avalanche fatalities occur at Considerable danger, a level where conditions can feel deceptively manageable. A rating of Low does not mean zero risk.
If there is no forecast for your area, treat that as a reason to be more conservative, not less.
Recognizing Avalanche Terrain
Avalanche terrain includes the slopes where avalanches start, the paths they run down and the areas where they stop.
Slope angle
Slopes between about 30 and 45 degrees are where most slab avalanches release. Slopes under 30 degrees rarely slide, but they can still be hit by avalanches coming from steeper terrain above. An inexpensive slope meter, or a slope angle feature on some mapping apps, can help you estimate angles. Many mapping apps also offer slope angle shading layers that highlight terrain steeper than 30 degrees.
Runout zones
Avalanches can travel a long way. Flat ground at the bottom of a steep slope may be in the path, even though the ground under you is level. Valley floors, frozen lakes below steep slopes and the bottom of gullies can all be runout zones.
Terrain traps
Terrain traps are features that make the consequences of an avalanche worse. They include gullies, creek beds and depressions where snow piles up deeply; cliffs where a slide could carry you over a drop; and trees or rocks you could be swept into. Even a small slide into a terrain trap can bury a person deeply.
Signs of avalanche activity
Clues that the snowpack is unstable include:
- Recent avalanches on similar slopes
- Shooting cracks in the snow around you
- “Whumpfing” sounds, which happen when a weak layer collapses
- Heavy new snow or rain in the past day or two
- Strong winds moving snow, creating drifts and cornices
- Rapid warming, especially after cold weather
Any of these is a strong reason to stay off and away from steep slopes.
Choosing a Safe Winter Campsite
Your campsite is where you spend the most time, often in the dark and while asleep, so it needs to be outside avalanche terrain entirely. Our guide on how to choose a safe campsite covers general site selection. In avalanche country, add these checks:
- Look up, not just around. Make sure there are no steep, open slopes above you that could release and reach your camp.
- Stay out of gullies and valley bottoms below steep slopes. These are classic runout zones and terrain traps.
- Avoid camping near the base of cornices, overhanging lips of wind-packed snow along ridges that can break off.
- Be cautious with scattered trees. Dense, old-growth forest can indicate an area that rarely slides, but avalanche paths often show as strips of open snow or small, broken or bent trees between taller forest.
- Consider the forecast for the whole stay. Snowfall or warming overnight can raise danger while you sleep.
Low-angle, open terrain well away from steep slopes, or dense forest on gentle ground, is generally the safest place to camp.
Planning a Route
Before your trip, look at maps and the avalanche forecast together.
- Identify any slopes over 30 degrees on or above your route.
- Look for alternative routes that avoid crossing below steep slopes.
- Decide in advance what conditions would make you turn around.
- Plan where you will camp and have a backup site.
If you cannot avoid crossing avalanche terrain, cross one person at a time, move quickly, do not stop in the path, and keep others watching from a safe spot. These practices are taught in avalanche courses and are best learned with hands-on practice.
Strong navigation skills matter in winter, when trails are buried and landmarks look different. Our guide to map and compass basics is a good place to start, alongside a GPS app with offline maps.
Essential Avalanche Rescue Gear
If you travel in or below avalanche terrain, every member of the group should carry three items and know how to use them:
- Avalanche transceiver (beacon). Worn on the body and set to transmit, it lets companions locate a buried person by signal. Switch it to search mode to find others.
- Probe. A collapsible pole used to pinpoint the exact location and depth of a buried person.
- Shovel. A sturdy, metal-bladed avalanche shovel for digging out a buried companion. Snow from an avalanche often sets up hard, like concrete.
This gear only helps if your companions have it too and can use it quickly, because they are the people most likely to rescue you. Survival chances for a fully buried person drop sharply with time, which is why fast companion rescue matters far more than waiting for outside help.
Some backcountry travelers also carry an avalanche airbag pack, which can help keep a person near the surface in some avalanches. An airbag does not replace a transceiver, probe and shovel.
A way to call for help, such as a satellite messenger or personal locator beacon, is also important in remote areas with no cell coverage. Our guide on satellite messengers vs. PLBs compares the options.
Get Training
Reading about avalanches is useful, but it is not enough. Recognized avalanche courses teach you to read forecasts, recognize terrain, assess snowpack, make group decisions and practice rescue.
In the United States, programs such as AIARE (American Institute for Avalanche Research and Education) and others recognized by the American Avalanche Association offer introductory courses. A common path is:
- Avalanche awareness sessions, often free and a few hours long, offered by avalanche centers, outdoor shops and clubs.
- Level 1 or introductory recreational courses, usually about three days with field time.
- Companion or avalanche rescue courses, focused on transceiver, probe and shovel skills.
Avalanche Canada offers similar Avalanche Skills Training courses. Many avalanche centers also post free online tutorials.
Human Factors
Avalanche educators emphasize that many accidents happen not because people lacked information, but because of decisions made in the moment. Common traps include:
- Familiarity: feeling safe in a place you have visited before.
- Commitment: pushing on because you drove a long way or planned the trip for weeks.
- Group pressure: not speaking up when something feels wrong.
- Following tracks: assuming a slope is safe because others have been on it.
Agree as a group that anyone can call for a more conservative choice at any time, without argument. Turning around is always an option.
Safe Winter Trips Without Avalanche Terrain
You do not need to travel in avalanche terrain to enjoy winter camping. Many great winter trips stay entirely in low-angle terrain, where the main hazards are cold, weather and navigation rather than avalanches.
Good options include groomed or packed trails in state parks and national forests, rolling forest roads closed to vehicles in winter, frozen meadows far from steep slopes, and established winter campgrounds. Some areas also offer yurts or warming huts reachable by gentle trails. Ranger stations and avalanche centers can often suggest routes that stay out of avalanche terrain.
Starting in this kind of terrain lets you build winter skills, such as setting up camp in snow, keeping warm and managing water, without adding avalanche risk. Once you have training, you can decide whether to venture into more complex terrain.
A Simple Pre-Trip Checklist
- Read the full avalanche forecast for your area and elevation.
- Check the weather forecast for new snow, wind and warming.
- Review your route on a map with slope angle shading.
- Pick a campsite and backup site out of avalanche terrain and runout zones.
- Make sure everyone has a transceiver, probe and shovel if you will be in or below avalanche terrain.
- Check transceiver batteries and do a group transceiver check at the trailhead.
- Pack the rest of your winter safety gear, including warm layers and first aid supplies.
- Leave your trip plan with someone at home.
Cold is a hazard in its own right in the mountains. Our guide to hypothermia and frostbite explains the warning signs.
Questions People Ask
Frequently Asked Questions
Do I need to worry about avalanches on a snowshoe trip?
It depends on the terrain. Snowshoers can trigger avalanches just like skiers. If your route crosses or passes below slopes steeper than about 30 degrees, avalanche safety applies to you.
What slope angle is dangerous for avalanches?
Most slab avalanches release on slopes between about 30 and 45 degrees. Lower-angle slopes can still be hit by avalanches from steeper terrain above.
Where can I find an avalanche forecast?
In the United States, Avalanche.org links to regional avalanche centers. In Canada, Avalanche Canada publishes forecasts for many regions.
Is a transceiver enough to keep me safe?
No. A transceiver, probe and shovel are rescue tools, and they only help if your companions carry them and know how to use them. Avoiding avalanche terrain when danger is elevated is the most important safety measure.
