Moei River The Moei River forms the border between Thailand and Burma. The river is the scene of clashes between the Tatmadaw and Karen militias. Often Karen people cross the river either in order to enter Thailand as refugees or to go back to Burma. Moei River The Moei River (, , , ) is a tributary of the Salween River. Unlike most rivers in Thailand, the Moei River flows north in a northwest direction. It originates in Phop Phra District, Tak Province, flowing then from south to north across Mae Sot, Mae Ramat, and Tha Song Yang Districts, finally entering the
River systems of Thailand Mekong River Commission. The extreme seasonal variations in flow and the presence of rapids and waterfalls have made navigation extremely difficult. Approximately half the river's length is in China, where it is known as the "Lancang Jiang" (澜沧江 Láncāng Jiāng) or "Meigong" in Chinese (). The river forms the border between Myanmar and Laos for , at the end of which it meets the tributary Ruak River at the Golden Triangle. This point also marks the division between the "Upper" and "Lower Mekong". The river then divides Laos and Thailand, before a stretch passing through Laos alone. It is known