[3][4] Tons Valley lies in Jaunsar Bawar region, as it emerges from the Himalayas has haridwar on its eastern bank.

The Asan is a confluence of two small river systems, one comprising streams flowing south from the Himalayan range running from Vikas Nagar towards Tehri (with Mussorie in the centre), and the other comprising streams flowing north-west from the lower Shiwalik hills (that separate Dehradun and Saharanpur districts).

The misnomer Tons stands for the river originating from the Mussorie hills, flowing down through Robber's cave, Bijapur canal and Tapkeshwar Mahadev, before emerging into a broad valley behind IMA.

The theory[6] states that the Tons river became a tributary of the Yamuna a few thousand years ago following a tectonic event in the Shiwalik range near Sirmaur district of Himachal Pradesh.

[8] Visitors can stay at Jaunsar Bawar region on the banks of the Tons river and enjoy the grade 4 rafting.