Relacionar Columnas Stages of a river: features and characteristicsVersión en línea To relate key information about the different parts of a river. por Elvira Garcia Arnal 1 Source 2 Middle course 3 Lower course 4 Upper course 5 Mouth 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.