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 Upper course 2 Source 3 Lower course 4 Mouth 5 Middle course The end. A delta or estuary can be there. 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 water flows more slowly than in the upper course and there are meanders.