Teesta River

The Teesta River is said to be the lifeline of the Indian state of Sikkim, flowing for almost the entire length of the state and carving out verdant Himalayan temperate and tropical river valleys. The river then forms the border between Sikkim and West Bengal before joining the Brahmaputra as a tributary in Bangladesh. The total length of the river is 309 km (192 mi) It drains an area of 12,540 km?. Before a large part of this was situated in Nepal. But after the Sugauli Treaty it was acceded to British India.