River systems of Thailand used for the whole river. The river is long. It then leaves China and meanders through Myanmar (where it is known as the "Thanlwin") and Thailand (where it is known as the "Salawin", Thai: สาละวิน) on its way to emptying into the Andaman Sea by Mawlamyaing (Moulmien). The principal tributaries of the Salawin which flow through Thailand are the Moei River and the Pai River. In addition to the Salween River, there are a number of rivers which drain into the Andaman Sea from the west coast of the Malay Peninsula. None of them are extensive enough to be considered
Mae Hong Son Province Moei, ). Most of the areas of Mae Hong Son Province are the complex mountain ranges of the Thai highlands, parts of which are still covered with rain forest. Of the approximately 6,976,650 rai of national forest reserves, it is estimated that 88 percent is pristine virgin forest. The Daen Lao Range, in the northernmost portion of the province, marks the northern boundary between Thailand and Burma, while the Dawna Range in the west serves as the boundary between Thailand and Burma. The Thanon Thongchai Range in the east of the province serves as the boundary between the provinces of