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