Even in the desert, there are sources for water. We aren't covering desert survival here, so I will concentrate on water sources in the woods.
The first is the most obvious; streams, creeks, springs, lakes, and the like. In a mountainous terrain, water will most likely be found in gullies. This may seem like common sense, but many people make the mistake of looking for water in the wrong place.
We can often find sources of water by looking at vegetation, and it is a good idea to have an idea of what water loving plants look like in the area you are going into. For instance, River Willow will always be found near water. (For an idea of what it looks like, check
www.google.com, click Images, then search for Willow.) Sometimes you will find no obvious water around river willow, but in that case, there will be water if you dig far enough for it.
Watching animals can also be telling. For instance, if you see ducks flying, they are probably flying to or from water. Deer make trips to and from bedding grounds to feeding areas to water on a daily basis.
Snow and ice are good sources of water, but there is a warning. DON'T eat it, rather, if you have no containers and haven't yet created any, put it in your mouth and suck on it, drinking the water as it melts. Eating snow and ice can actually dehydrate you.
Also, many plants contain large amounts of water in them. Usually it isn't the greatest idea to use those juices for a water supply unless you are suffering from dehydration. The reason is that it also always contains starches and sugars. As our bodies digest them, they use water to do it. If you are dehydrated, then it can help as a temporary measure.