The Mun River (Thai: แม่น้ำมูล, RTGS: Maenam Mun, pronounced [mɛ̂ː.náːm mūːn]), sometimes spelled Moon River, is a tributary of the Mekong River. It carries approximately 26 cubic kilometres (6.2 cu mi) of water per year.
The Mun River in the dry season, Ubon Ratchathani
Map of the Mun River drainage basin
|⁃ location||Nakhon Ratchasima|
|⁃ elevation||530 m (1,740 ft)|
|Amphoe Khong Chiam, Ubon Ratchathani province|
|97 m (318 ft)|
|Length||900 km (560 mi)|
|Basin size||119,180 km2 (46,020 sq mi)|
|⁃ location||Mekong River, Ubon Ratchathani|
|⁃ average||725 m3/s (25,600 cu ft/s)|
|⁃ maximum||10,015 m3/s (353,700 cu ft/s)|
|⁃ left||Chi River|
|⁃ right||Lam Dom Noi|
The river begins in the Khao Yai National Park area of the Sankamphaeng Range, near Nakhon Ratchasima in northeast Thailand. It flows east through the Khorat Plateau in southern Isan (Nakhon Ratchasima, Buriram, Surin, and Sisaket Provinces) for 750 kilometres (466 mi), until it joins the Mekong at Khong Chiam in Ubon Ratchathani. The Mun River's main tributary is the Chi River, which joins it in the Kanthararom District of Sisaket Province.
Thanks to the Andy Williams hit song, the Mun River was called "Moon River" by US Air Force personnel stationed at Ubon Ratchathani airbase during the Vietnam War. The spelling is still fairly common.