One survival skill that has always piqued my interest is snow cave building. It is something that I have seen and read about, but never had the chance to actually try out.
This past weekend, I had the opportunity to ease my curiosity, as I found myself on top of a mountain with no other means for shelter than a snow cave.
How to build a snow cave
Go up into the mountains…
Typically, snow caves are used as an emergency survival shelter in high altitudes. In order to build one, you need go somewhere with several feet of packed snow. It also helps to find an area that is on an incline that you can dig into. Just be sure the slant is less than 25 degrees in order to minimize the risk of an avalanche.
Start digging a tunnel…
In a perfect world, you should have a packable snow shovel with you whenever you’re up in the backcountry during winter. In this case, I only had my bowie knife to help me dig through the snow. And although it worked to get the the job done, carving out a cave is definitely not its intended purpose.
Ideally, the tunnel should only be wide enough to crawl through, to minimize cold air entering the cave. It should also slope slightly downward, which will serve as a cold well and allow the warmer air to rise into the chamber of the cave.
Dig out a dome shaped chamber…
Once you’ve dug in about 2 or 3 feet, begin digging the main chamber. As with the tunnel, you should only hollow out the cave tall enough to have a little head room when you sit up and just wide enough to create a sleeping area and space for your gear.
The larger you build, the larger the area that has to be heated in order to stay warm, and the more energy you have to expend constructing it. In a pure survival scenario, sometimes less is more.
Make a shelf to sleep on…
After you have a little more room to work, you need to make an elevated platform to lay on. This next part may seem trivial, but you should always try to make this shelf as flat and level as you can. Trust me, you’ll be thankful not to slide down to the bottom of your shelter while you sleep.
Create a ventilation hole in the ceiling…
This is arguably one of the most important steps to building a snow cave. Using a stick, or a ski pole, poke one or two holes all the way through the ceiling for ventilation. This will allow the carbon dioxide you exhale to escape the cave as well as let some fresh air in.
Make a barrier between your body and the snow…
Lastly, you need to make sure to keep your body up off the snow during the night. The best way to do this is to layer a tarp, then inflatable sleeping pad, and finally, a sleeping bag. If you do not have a pad and tarp, you can use layers of evergreen boughs, but expect a very cold and uncomfortable night.