Entrance to a Snow Cave

Survival Skills: Building a Snow Cave

With the snowiest months ahead of us here in Colorado, a lot of people will be getting out for skiing, snow shoeing, and cross country skiing, or maybe even a little fishing on any rivers that are free of ice.  Regardless of what takes you into the mountains, there is always the risk of being stranded by deep snow or a storm.  Even if you aren’t in the mountains, there are times when traveling in the winter time where you may find yourself stranded and in need of an emergency shelter.

Hopefully whether you are on foot, snow shoes, skis, or in your car, you have some survival gear that would include a tarp and some para cord to make a shelter.  But if you don’t, you always have the option of building a snow cave for shelter, or you maybe even planned on building a snow cave for shelter on your cross country ski trip.  Whatever your situation, the ability to build a snow cave is an excellent survival skill to have.

A snow cave can protect you from the cold, snow, and wind, and even with a single candle will be up to 20 degrees warmer that the outside temperature.  Add in a sleeping bag, and you can be quite comfortable in a snow cave even in sub-zero temperatures and blistering winds.  If you are in a survival situation, it is important to remember to make your snow cave visible from the outside.  I suggest using a lodge pole pine, or something similar, with bright colored clothing tied to it high above the snow.  Also, check out the surroundings and don’t build your cave in a potential avalanche chute. It’s also important to remember that when you are in the snow cave, you can’t hear much at all of what is going on outside of the cave, such as rescuers calling for you.


Snow Cave Under a Tree

There are a few options for building a snow cave, the option that is right for you depends on your situation, and what you have available.  For example, a lost hunter can easily build a snow shelter at the base of a large pine or spruce tree that has a large amount of snow piled up on the down-slope side of a mountain.  Or if you are traveling by car and find yourself stranded, the northern side of a roadway is likely to have large snow banks that you can dig into.  If you are in an area where there is four or more feet of snow on the ground, you can build your shelter by digging down to the ground as your entrance tunnel, and piling everything you dig out onto the top of your shelter.  If you are in an area without deep snow, deep drifts, or snow banks to dig into, you can pile snow into a very large mound (keep in mind that if you use this technique, you need to let the pile of snow crystallize for at least an hour before you try to carve into it).

One of the most important factors in building a snow shelter is what you have in your possession to use for digging.  If you have an avalanche shovel attached to your pack, you will be in a much better position to build a snow cave.  If you don’t have an avalanche shovel, you can use a spade, a cooking pot, a solid plate, or even a stiff piece of plastic.  If you have none of these, you can use your hands or whatever device you might have available, even a CD from your music selection will work.  Just be sure that you are properly dressed when you dig as you will get wet building a snow shelter, and wet + cold = death.


Snow Cave Interior

While you may need to adjust these instructions, here are the basics to building a snow cave or snow shelter.

· Once you have your snow bank or pile of snow identified as your shelter, go to the lee side (the direction the wind is blowing towards, this will usually be the southeast side of the shelter).

· Starting from your proposed entrance to the snow cave, dig a trench 8 feet long as deep as you are tall.  I realize this isn’t always possible, but this is the ideal.

· Start digging an entrance tunnel in an upward direction.  You want an entrance tunnel to be about 6 feet long if possible, and incline at an angle towards the entrance so that the floor of the cave is at least a foot above the entrance.  The tunnel should be about twice as wide as your body.  If you are not alone, always have another person outside of the cave in case there is a collapse so they can dig you out.

· Start carving out the cave and pushing the snow out behind you.  This is a difficult task, especially if you are alone, and it can take hours to do this work.  Keep in mind that you want at least 12 inches of snow for the roof and walls, and you can gauge this by inserting 12 inch twigs in several places from the top before you start carving. If you start hitting those twigs, you know you are reaching the minimum thickness of the walls and roof.

· Once you start forming the interior of the cave, carve out a shelf on the far end for a sleeping platform, or shelves on the sides for multiple people.  The sleeping shelf should be at least 18 inches above the floor of the cave.

· Carve out additional smaller shelves for candles and gear.

· Cover the floor and sleeping benches with pine boughs, extra clothing, or a tarp.

· Poke an air hole about two inches in diameter about a third of the way to the apex of the ceiling, and be sure to check often that it remains clear.

· Finish off the walls and the ceiling with a gloved hand; try to smooth out the surfaces as much as possible, particularly on the ceiling, as any bumps will begin to drip as the temperature inside the cave warms up.

· Use a block of snow or a pack to cover the entrance to the cave to help keep in the warm air.

· Always keep your digging device with you as you may need to dig your way out if the shelter collapses or a storm covers your entrance.

Those are the basic concepts of building an emergency snow shelter.  It is amazing how much a shelter such as this can increase your chances of survival.  I have not been in a situation to have to rely on building a snow cave for shelter, but I do practice building them whenever I can, it is actually a fun thing to do.


Kyle in his collapsed snow cave

In 2006 we had a massive snow storm here that dumped over 33 inches of snow in a little more than a day, and my son Kyle and I were trapped in our house.  Luckily I had all the things we needed because we didn’t get out for four days.  But I used that time to teach Kyle how to build a snow cave in the front yard, and he made a very nice cave.  After a few days as the temperatures warmed up the cave weakened and eventually collapsed, but it was a great learning experience, and a ton of fun to do that together.