The Yuan or Yüan River (Chinese: 沅江, p Yuán Jiāng or 沅水, Yuán Shuǐ) is one of the four largest rivers in Hunan province in southeast-central China. It is a tributary of Yangtze River. It is 864 kilometres (537 mi) long and rises in Guizhou province in the Miao Mountains near Duyun and is navigable. The upper stream is called the Longtou River, and downstream it is called the Qingshui ("Ch'ing-shui") River. It becomes the Yuan River after its confluence with its northern tributary, the Wu River.