Mahananda River
The river has its origins in Chimli, Kurseong in Darjeeling District. The Mahananda River in its course of descent from the hills runs through a subterranean area and comes into sight after a distance of four miles. It alters its route at Siliguri and from there it enters the Jalpaiguri district. Its total catchment area consists of more than 25,000 sq km. It has three tributaries called the Trinai, Ranochondi and the pair of Chokor and Dauk taken as a single tributary. The river is also joined by the Balasun while in its course downhill.

An iron bridge with a railway track spans the river on the western side of Siliguri town; the Mahananda bridges connecting the two parts of the town runs over the eastern side.

The Mahananda in its unending course flows through North Bengal, Bihar and finally enters Bangladesh; from there it again enters Malda and joins the Ganges in Bangladesh.
Siliguri and Malda are the two important settlements situated alongside the Mahananda River.

Teesta River
The Teesta River is one of the most important rivers of North Bengal. It is revered, feared and adored by the people for the mystery and power it exudes. The source of the Teesta lies at an altitude of 17,500 feet at Cho Lhamu Lake in the Himalayas.

As the river flows downhill, it is fed by smaller streams like the Yumthang, Donkia-la and Thangu. The Teesta River also forms the boundary between Sikkim and West Bengal near Teesta Bazar. Below the Teesta Suspension Bridge it joins its primary mate, the Rangeet River. The river then enters the plains at Sevoke and is spanned by the Coronation Bridge that connects the North East States to the rest of India. From here again, the river enters Jalpaiguri and finally merges with the great Brahmaputra River in Bangladesh.