Ramganga River is the Lifeline for Corbett National Park. We cannot imagine the existence of Corbett without Ramganga. It is the largest of all the precious water bodies in the park. The river flows around a stretch of near about 100 kilometers before you get inside the park near Marchula. Approximately, it flows 40 Kms east to west inside the park till Kalagarh where it meets plains.

The Kosi is a perennial river that servers major portion of the Corbett's wild as the Corbett wild use the Kosi river to quench their thirst. Eastern periphery of the park is fed by Kosi that flows from Mohan till Ramnagar via Dhikuli. Though, the Kosi does not enter the park boundary.

This gorgeous river is the significant tributary of Ramganga River. The river has been named after the Sonanadi wildlife Sanctuary that adjoins Corbett National Park and held as an crucial part of Corbett Tiger Reserve. It enters the Corbett from the North-West direction and merges into the Ramganga River at its reservoir.