Anyone who might someday get lost while hiking, hunting, canoeing or backpacking should know the basics of how to build a wilderness survival shelter. There are several types, ranging from snow caves to poncho tents to modified rock-ledge shelters. They all have their place, but this article will cover just one: the lean-to.
One advantage of a lean-to is that it can be built almost anywhere there are trees. Another is that it requires no tools. Finally, it can be built with a variety of materials.
The most basic design starts with a small tree or pole or stick which is lodged horizontally in the branches of two trees. This is the peak of the roof, and so should be high enough so you can be comfortable inside the finished shelter, but also low enough in cool weather so the space created can be warmed (at least in part) by your body heat. The length should allow for you to stretch out underneath.
Against this main “roof beam” you lean any sticks you can find. Interweave a few horizontally for added strength. At the sides lean other smaller sticks to further enclose the space. If you leave one side open you can have a fire in front. Otherwise you can lean sticks on the other side of the beam as well, creating a kind of “a-frame” shelter (leave a hole to crawl inside).
To keep out wind and precipitation (the primary purposes of a survival shelter), you’ll need to “shingle” your roof. This can be done using flat evergreen boughs (just break the lower ones off small trees), bundles of grass, large pieces of tree bark, or even pieces of plastic and junk, depending on your circumstances. The important point here is to start by laying the materials against the bottom, where the roof slopes to meet the ground, and then add overlapping layers higher up.
Done right, a shelter like this can be made in an hour or so and keep out most rain, snow and wind. Unless you do plan to have a fire in front for warmth, keep the shelter small. In this way the heat from your body can keep the space heated to at least several degrees warmer than the outside air.
It can help to have some way to tie sticks together, so experiment with any vines or pliable branches and strips of bark you see. Some evergreen roots work well too, and can be found in the soft soil less than an inch deep.
If you plan to have a fire, make the opening of the shelter parallel to the expected direction of the wind. This will minimize the amount of smoke you breath. Facing away from the wind will actually cause some smoke to swirl back into the shelter.
Always provide some way to keep yourself off the ground as much as possible, since it can steal a lot of body heat. Make a mattress of dry leaves or grass. You can also make a mattress using fir boughs (unlike spruce, these have flatter and softer needles). Stick the broken ends in the ground and work towards them so the branches are layered like shingles, with only the soft tips above.
If you don’t have a fire, make a “door” or covering for the opening. In this way you can close yourself in to trap your body heat.
A lean-to is one of the best wilderness survival shelters because it is so adaptable. Look for other arrangements, like starting with a downed tree you can fit under and building a lean-to using that as the roof beam. Even a partial cave or rock overhang can be enclosed with a simple lean-to.