|NATIONAL PARKS QUICKLINKS|
Should you use 'em? How to make 'em.
Moonrise over Raimondi Glacier, Huascaran, Peru. Pic: howephoto.us
Sooner or later, most winter campers end up sleeping in shelters dug out of, or sawed into, the snow. Tree-wells, snow trenches, snow caves, quinzhees, and igloos can be secure to live in and fun to make. But snow shelters aren't for everyone or every trip. Read on to learn the fortes, foibles, and a few tips about making and living in various snow shelters. Here's we'll start with the simple stuff, then deal with igloos and such in my next dispatch.
First off: Snow shelters versus tents
Tents Pro: They're quick and easy to pitch. You can put them anywhere that's flat, dug out or packed down. Good ones can stand up to most any weather.
Tents Con: They’re cold in subzero conditions, noisy in wind, and heavy. Four-season two-person tents usually weigh 6 to 9 pounds once they're rigged with guys, stake-out loops, or deadman anchors.
Snow Shelters Pro: They're secure in wind and quiet in noisy environments. Even in frigid weather, caves, quinzees and igloos are very warm (usually just above freezing inside). They're fun to build and rewarding to live in. They can save your life in an emergency. The can make great base camps and wilderness ‘forts’ for repeat visits.
Snow Shelters Con: You need waterproof shell clothing, spare mitts or gloves, a shovel, or a snow saw to make them, so figure those items into your ‘ultralight’ shelter weight. They can be slow to build, and you can get soaked doing it. The insides are humid and steamy, so you need water resistant gear. Be very careful cooking in a snow shelter, it’s easy to get carbon monoxide poisoning. Last but not least, you need the right snow conditions.
The upshot: Be careful of relying on snow shelters for committing thru-hikes, where you might not find suitable conditions, or have the time to erect one each evening. Always take along emergency shelter, like a tarp or tarp tent. That said, here are your snow shelter choices, from simple to elaborate.
Tree well pits: In decent weather or moderate storms, a pit dug into the ‘tree well’ beneath any large evergreen might be all the shelter you need. The overhanging branches provide a shield from spindrift and the chilling effects of open sky, while the snow walls protect you from wind. In ideal conditions, you can shovel the snow walls high enough that they support the tree’s lower branches, forming a completely enclosed space.
Snow trenches: Another simple survival shelter is a snow trench, dug large enough for a sleeping person to lie down or sit up in without touching the ceiling or walls. Two people can lie head to head in a long trench, with a kitchen area between them, and an entrance on each end. You can cover the trench with skis, ski poles and a tarp (drips can be a problem with this method), or use large snow blocks angled to form a long, peaked A-frame roof (this requires two people or a lot of juggling). Snow trenches are quick and easy to build, but not particularly warm, since hot air naturally rises up out of them. They can also become deeply drifted in during blizzards.
Snow caves: Are the most stormproof shelter you can possibly slide into, but you pay for that with a lot of digging, and you can get soaking wet while doing so. Always wear full shell gear and a hood when digging out a cave. Start by finding a wind-drift with a vertical face on it, like the wind-well around a boulder, or a ridgetop cornice (beware, since cornices can be a sign of avalanche danger). You’ll need a snow drift at least 6 feet deep and 10 feet front-to-back for a decent sized cave. Start by digging into the snow face as low as possible. Tunnel the entrance back about four feet, then begin digging up to reach the intended floor level of your cave.
Suck it up and keep digging, hollowing the space up and outward. It’ll take at least two hours for two people to dig out and finish up a decent sized cave. One person digs while the other clears snow from the tunnel entrance. Whenever you start to see light through the snow ceiling, you’re getting too close to the surface. Use a stick, avalanche probe, or ski pole with the basket removed to check roof thickness.
Arch the cave roof into a dome shape for strength and drip-resistance. Don’t wander off and leave your companion digging alone, since a collapsed roof might require quick rescue work. Finish the cave off by scrupulously flattening the floor, smoothing the roof as evenly as possible, and carving any benches or shelves you might require. One luxurious layout is to make a bench bed on each side of the cave, with a knee-deep trench running in at door level, so you can comfortably sit up inside the cave, and stand up while dressing or entering.
Poke several vent holes through the ceiling (you can plug them easily with a snowball if needed). Snow caves can be very airtight, especially once your body heat and breath condensation form an ice layer on the inner surface. Never close the door off tightly, and keep it shoveled open during blizzards. A pack, shoved into the entrance, is plenty of closure for most conditions. If you’re staying several nights in your cave, you can keep expanding it a little more each day. Snow caves work well for fixed camps you return to often, but in warmer winder conditions they slowly flow and collapse, so expect to shovel the roof back to proper height every couple days. Don’t walk across the cave roof either, or you’ll become very unpopular with your buddies.
O.K., that's all for now. Next post, up soon, is on Quinzhees and igloos. Until then, stay warm campers. -- Steve Howe