The Yarlung Tsangpo is the part of Brahmaputra River that flows through Tibet, known by its Tibetan name. It originates at Angsi Glacier in western Tibet southeast of Mount Kailash and Lake Manasarovar. It later forms the South Tibet Valley and Yarlung Tsangpo Grand Canyon before passing through the state of Arunachal Pradesh, India, where it is known as Siang.