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
Sai River (Thailand) Sai River (Thailand) Sai River (; ; ), formerly known as the River of Lawa (; ), is a river that forms the natural border between Thailand and Myanmar at Tachileik and Mae Sai Districts. Mae Sai town, where the bridge crossing the international border is located, is named after this river. It is a tributary of the Ruak River, itself a tributary of the Mekong. The river has its sources in the Daen Lao Range, in Shan State, Myanmar. Then it flows southeastwards, bending eastwards at the feet of the northern end of the Doi Nang Non ridge before