Rinkhyong River  a number of small streams originating from eastern hills of Mizoram (India) and meeting together at the uppermost part of the Rinkhyong reserves are known as Rinkhyong. The river makes a torturous journey through the deep reserve forests and falls into kaptai lake near Belaichhari (Rangamati) about 30 km above Rinkhyongmukh, its original place of confluence with the karnafuli. The river is flashy and is 77 km long. It is navigable up to Gobachharimukh during wet season and further above it is used only for floating timber and bamboo. [Jabed Kalim]

See map in chittagong region river system.