river of eastern Guizhou (Kweichow) and western Hunan provinces, southeastern China. The Yuan River is about 635 miles (1,020 km) long and rises in the Miao Mountains near Duyun in Guizhou. Its upstream sections are called the Longtou and Qingshui rivers. It becomes the Yuan River after its confluence with its northern tributary, the Wu River, which flows through Zhijiang. It then flows northeast along the western flank of the Xuefeng Mountains in Hunan to discharge into Dongting Lake at Changde and then into the Yangtze River (Chang Jiang). The Yuan is a major waterway for western Hunan and eastern Guizhou. Large vessels on it can reach Changde, and small steamboats can travel as far as Taoyuan. Above this there are rapids, but shallow-draft junks can reach Hongjiang near the Guizhou border and can travel up the Wu River as far as Zhijiang. Although there are highways running through the Yuan valley, the river is still an important means of transport for the mountainous areas of western Hunan.