Manas River

The Manas River (Pron: ˈmʌnəs) is a transboundary river in the Himalayan foothills between southern Bhutan and India. It is named after Manasa, the serpent god in Hindu mythology.It is the largest river system of Bhutan, among its four major river systems; the other three are Amo Chu or Torsa, Wong Chu or Raidak, Mo Chu or Sankosh. It is met by three other major streams before it again debouches into India in western Assam. The total length of the river is 376 kilometres (234 mi), flows through Bhutan for 272 kilometres (169 mi) and then through Assam for 104 kilometres (65 mi) before it joins the mighty Brahmaputra River at Jogighopa. Another major tributary of the Manas, the Aie river joins it in Assam at Bangpari.

The river valley has two major reserve forest areas, namely the Royal Manas National Park (43,854 hectares (108,370 acres), established in 1966) in Bhutan and the contiguous Manas Wildlife Sanctuary (391,000 hectares (970,000 acres) in 1955 increased to 95,000 hectares (230,000 acres) in December 1985) encompassing Project Tiger Reserve, an Elephant Reserve and a Biosphere Reserve, which constitutes a UNESCO World Heritage Site declared in December 1985.