Matching Pairs Stages of a river: features and characteristicsOnline version To relate key information about the different parts of a river. by Elvira Garcia Arnal 1 Source 2 Upper course 3 Lower course 4 Mouth 5 Middle course The water flows more slowly than in the upper course and there are meanders. Initial stage of the river. You can find rapids and waterfalls. The start. It is often a place in the mountains. The end. A delta or estuary can be there. The final stage near the coast.