Tons River

The Tons (टौंस नदी) is the largest tributary of the Yamuna. It flows through cultural Mahasu region in Uttarakhand and Himachal Pradesh, marking the boundaries of the two states after Tyuni, where the confluence of the Tons and rivers occurs. The Tons thrust is named after this river.

With its source in the 20,722 feet (6,316 m) high Bandarpunch mountain, it is one of the major perennial Indian Himalayan rivers. In fact, it carries more water than the Yamuna itself, which it meets below Kalsi near Dehradun, Uttarakhand.