The Yarlung Tsangpo runs west to east for along the north slope of the Himalayas, but south of the Transhimalaya ranges of the Gangdise Shan and Nyenchen Tanglha Mountains. The ecoregion mostly follows the river valley and short tributary valleys, including the area north to Lhasa. Yamdrok Lake, one of the largest lakes of the Tibetan Plateau is in the region, and at Lhasa is an urban impoundment of water now protected as the Lalu Wetlands National Nature Preserve.