In spite of what the average would-be survivalist would think expect from Hollywood movies and T.V. shows, in a real wilderness survival situation, procuring drinkable water is essentially the number one priority for staying alive. While it is true that, in such a situation, you may be attacked by wild animals, you may get into squabbles with other people who are stuck in the same situation, and in time you may even starve: but before any of this can happen, if you do not get at least two liters of water in your body every 24 hours, you will be dead long before any of these things will become a problem.
The most obvious answer to the question of where to find water in the wilderness is in rivers, streams, and lakes, if you are lucky enough to be around them. If you are lost, one easy way of finding water is to observe the local wildlife: if there are birds in the trees, squirrels in the bushes, and so on and so forth, they have to be getting water from somewhere. This applies to smaller and more inconspicuous lifeforms as well: chances are, if you are being more frequently bitten by mosquitoes in one area than you were in another, water is not far away. Another tip is to follow the slope of the land downward: gravity naturally leads rainwater and melting snow downhill, so chances are if there is a downward slope, there will eventually be a stream.
However, even if you are lucky enough to find such a source of water, your troubles are not over yet. While dunking your head into the stream and drinking to your hearts content may make you feel better the moment you do it, you will probably pay for it later. Unlike the water the water that comes out of the tap at home, water in the wilderness most likely has at least some unsavory things in it that can make you sick further down the line. Furthermore, there will be times when water comes in the form of a nearly-try riverbed, with most of heavily mixed with muck and various other unsavory elements. But even if you don’t have an iodine pill handy, there are still ways to make the water more potable. By using cloth tied to sticks arranged in a tepee-like fashion, water can be gradually filtered into a container, removing many of the things you do not want in your body in the process. If you don’t have cloth handy, this can also be done by filtering the water through gravel or sand and letting it gradually drip down into a container.
Of course, you may not be able to find a stream or a lake no matter how hard you try. In this case, a simple device called a still, which can be made with something as simple as a clear plastic bag, some leaves and a rock. First, get as much air into the bag as possible, as by opening it so that the wind blows in it (you can create some artificial wind with your hand it no real wind is available. Next, put it green leaves and other vegetation until the bag is about 3/4 full – make sure it is all green, no sticks. After this, but the rock in the bottom and tie the bag tight so no air can escape. Place it in the sun, if possible on a slope so that the mouth is higher than the bottom, where the rock should be. Within 24 hours, you should have between a half a liter and a full liter of water – which means you will need to set about three or four stills to get all the water you need.