vast, high plateau of southwestern China. It encompasses all of the Tibet Autonomous Region and much of Qinghai (Tsinghai) province and extends into western Sichuan province and southern Uygur Autonomous Region of Xinjiang (Sinkiang, Uygur Autonomous Region of). The region lies between the Kunlun Mountains and its associated ranges to the north and the Himalayas and Karakoram Range to the south and southwest, respectively; it extends eastward to the Daxue Mountains and, farther south, the northern and central portions of the Hengduan Mountains. The plateau, which has an area of about 965,000 square miles (2,500,000 square km), is a region of tangled mountains and uplands that are generally above 13,000 to 15,000 feet (4,000 to 5,000 metres) in elevation. Mount Everest (Qomolangma Feng) (Everest, Mount), rising 29,035 feet (8,850 metres) above sea level on the China- Nepal border, is the world's highest peak (see Researcher's Note: Height of Mount Everest).

The northern section of the plateau, called Qiangtang, is dotted with many brackish lakes; its southern section contains the headwaters of the upper Indus (Indus River) and Brahmaputra (Brahmaputra River) rivers. Other rivers that have their headwaters in the highlands are the Yangtze River (Chang Jiang), the Huang He (Yellow River), the Mekong (Mekong River), the Salween (Salween River), and the Tarim (Tarim River). Grasslands are used for pasturage, and barley is grown on the plateau; forests grow on the slopes of valleys, particularly in the south. The most extensive farming in Tibet takes place on the fertile plains of the Brahmaputra River and its tributaries. Lhasa, the capital of Tibet, is the plateau's major centre of population, economic activity, culture, and air and land transportation.