Salween River much of its length, the Salween's course is nearly parallel to that of the much larger Mekong in the east. Although the commonly accepted name is Salween, the river is known by a handful of other names regionally: "Nu" in China, "Thanlwin" in southern Burma, and "Salawin" on the border of Thailand and Burma. Several major sub-continental drainage basins border on the Salween. The Mekong basin forms nearly the entire eastern boundary of the watershed, while the Irrawaddy River flows southwards on the west side of the basin. The smallest boundary is formed by the Yangtze to the extreme north.
Lao River (Thailand) Lao River (Thailand) The Lao River or Mae Lao River (, , ) is a river in Chiang Rai Province, Northern Thailand. It is a tributary of the Kok River, with its mouth near Sum Pratu in Mueang Chiang Rai District. This river gives its name to the Mae Lao District. The Lao River originates in the Phi Pan Nam Range and flows initially northwards across Wiang Pa Pao District and then northeastwards through the districts of Mae Suai, Mae Lao and Mueang Chiang Rai passing just south of Chiang Rai city. The Suai River, which gives its name to