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