The Salween is a Southeast Asian river, about 3,289 km (2,044 mi) long, flowing from the Tibetan Plateau south into the Andaman Sea. The Salween flows primarily within southwest China and eastern Myanmar, with a short section forming the border of Myanmar and Thailand. Throughout most of its course, it runs swiftly through rugged mountain canyons. Despite the river's great length, only the last 90 km (56 mi) are navigable, where it forms a modest estuary and delta at Mawlamyine. The river is known by various names along its course, including the Thanlwin (named after Elaeocarpus sp., an olive-like plant that grows on its banks) in Myanmar and the Nu Jiang (or Nu River, named after Nu people) in China. The commonly used spelling "Salween" is an anglicisation of the Burmese name dating from 19th-century British maps.
Due to its great range of elevation and latitude coupled with geographic isolation, the Salween basin is considered one of the most ecologically diverse regions in the world, containing an estimated 25 percent of the world's terrestrial animal species and thousands of plant species. Along its course the Salween provides water for agriculture and supports abundant fisheries, especially in the delta region. The Salween basin is home to numerous ethnic minority groups, whose ancestors largely originated in the Tibetan Plateau and northwest China. Starting about 5,000 years ago, people began migrating south along the river, establishing small kingdoms and city-states.
