Cho Lhamu Lakeat an elevation of 17,500 feet above the level of sea is the origin of River Teesta
River Teesta meets the Rangeet River, its chief tributary, at Teesta Suspension Bridge. The Teesta Suspension Bridge plays a key role in connecting Kalimpong and Darjeeling hillstation. After meeting Rangeet River, Teesta takes a southward turn and flows entirely into the state of West Bengal. At Sevoke where the Coronation Bridge is located, the river comes to the plains. Later, the river changes its route first to Jalpaiguri and afterwards to Rangpur District located in Bangladesh, before eventually flowing into the Brahmaputra River.