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 Lower course 2 Upper course 3 Mouth 4 Source 5 Middle course The end. A delta or estuary can be there. The water flows more slowly than in the upper course and there are meanders. The start. It is often a place in the mountains. Initial stage of the river. You can find rapids and waterfalls. The final stage near the coast.