Finding a pre-packed mound of snow is preferable to having to build one yourself. A 5-ft deep drift of settled snow against a downed mass of tree roots or something would be ideal, and would save a lot of energy at a time when you need to conserve what you've got. If you can't find a large enough mound, you'll either have to add to a small one, or make one from scratch. Then, you'll either have to pack it down, or give it some time to set, or all it is is a mound of loose snow that will collapse when you start digging into it.

Since everyone in the cave will be huddled together to conserve warmth, the size probably won't vary all that much. Besides, the size will be limited by the size of the snow mound. A sleeping area the size of a twin bed is fine for two people, a double bed for three, etc.

Once you have your mound, the first thing you need to do is mark the wall thickness, which should be about a foot or so. Find some thin branches, break them all to about a foot in length, and push then in to their length all over the snow mound.

If there are two or more people involved, make sure at least one is always outside the cave while you're digging. Snow caves have been known to collapse while under construction, although once finished, it doesn't happen very often.

Your cave opening should be on the downwind side of the mound. If you can, try to dig slightly upward, making a ramp-type opening just slightly larger than the crawling size of the largest person. If you can make the opening of the snow cave lower than the platform, you can probably eliminate taking the time to make a separate cold well. Since heat rises, you will want the sleeping platform to be the highest point inside, to trap whatever heat you can provide.

When you start carving upward, stop when you hit the tips of the branches you inserted from the outside. Try to carve the ceiling in an arc, so melting snow/ice will run down the walls instead of dripping onto you and the platform.

If you can pile fir or pine branches on top of the raised platform, it would help to insulate you from direct contact with the ice.

The 2" ventilation hole should be near the top of the mound. It doesn't need to be larger. Think of air as water, and you'll see how much air can pour in through a continously-open 2" hole, just like water can.

Find a long, slim stick and leave it in the hole, with the base on or near the platform. Move the stick to keep the hole open.

Block the opening of the entrance with a pack or other moveable object. Keep any digging equipment inside the cave, near you; if it snows a lot during the night, you may have to dig your way out.

Lighting a candle or tea light will increase the temperature in the cave, but will also use up oxygen, so make sure the vent hole is always open (the original 2" is fine). Keep in mind that although a candle will raise the temperature inside and improve moral, the temps in the cave will not rise much above freezing, so don't expect it.

Fires are not usually burned in snow caves, as the heat they give off is excessive, and will tend to melt the cave.

If you have children with you, please take the time to explain the WHY of everything you're doing, especially the vent hole. Not only will talking to them calm them, but they will be absorbing valuable knowledge. And if you fall asleep, they can help keep the hole open.

Also if you have children with you, tell them NOT to leave the cave just to pee. They will certainly get chilled, and possbily get lost, esp at night. You might want to dig a hole in a "corner" just for that purpose right in the beginning.

Sue