Most rivers start high up in the mountains. As the water comes down the hill, it makes little pathways in the rocks and gravel. As the pathways get bigger, they join to make streams. Sometimes the streams join together to make a river. Where a river leaves the mountains the ground flattens out, and the river slows down. The river ends when it flows into the sea.

The area in and around a river is a good place for plants, animals and people to live because we can all find food and water there. The salmon is an important food for many of us.