One of the world's great rivers, the Mekong begins in the melting glaciers of the Tibetan Plateau, in China's Qinghai Province, and ends some 3,ooo miles away, emptying into the South China Sea in southern Vietnam. Passing through Myanmar (Burma), Laos, Thailand, and Cambodia, the river traverses steep mountain gorges, daunting rapids, and immense alluvial plains in six nations. Its watershed encompasses 85 percent of Laos and Cambodia, one-third of Thailand, and smaller parts of Vietnam, Myanmar, and China.

More than 60 million people live in the Mekong basin--speakers of at least a hundred languages. Some of the region's ethno-linguistic ...