Siang

The Siang cuts through the eastern Himalaya on its way to the Assam plain. Known upstream as the Yarlung Tsangpo, the great river turns south through a deep gorge before emerging from the mountains. Near Sadiya it joins the Dibang and Lohit, and the combined waters continue as the Brahmaputra. Tributaries such as the Siyom descend through their own steep valleys to meet the Siang, linking a broad sweep of mountain country to the river below.