- Largest and most important tributary.
- It originates from the Yamunotri glacier on the Bandarpunch Peak in the Garhwal region in Uttarakhand at an elevation of about 6,000 meters.
- It cuts across the Nag Tibba, the Mussoorie and the Shiwalik ranges.
- It emerges out of the hilly area and enters plains near Tajewala.
- Its main affluent in the upper reaches is the Tons which also rises from the Bandarpunch glacier.
- It joins the Yamuna below Kalsi before the latter leaves the hills. At this site, the water carried by the Tons is twice the water carried by the Yamuna.
- It unites with the Ganga near Triveni Sangam, Prayagraj (Allahabad).
- The total length of the Yamuna from its origin till Allahabad is 1,376 km.
- It creates the highly fertile alluvial, Yamuna-Ganges Doab region between itself and the Ganges in the Indo-Gangetic plain.
The Sind
- The Sind originates in Vidisha Plateau of Madhya Pradesh.
- It flows for a distance of 415 km before it joins the Yamuna.
The Betwa
- The Betwa rises in Bhopal district (Vindhyan Range) and joins the Yamuna near Hamirpur.
- The Dhasan is its important tributary.
The Ken
- The Ken river rising from the Barner Range of Madhya Pradesh joins the Yamuna near Chila.
