The legendary Chamagudao, the Tea-Horse Road, winds through dizzying mountain passes, across famed rivers like the Mekong and the Yangtze and past monasteries and meadows in a circuitous route from Sichuan and Yunnan Provinces in western China to the Tibetan capital city of Lhasa. Actually a network of roads, trails and highways, rather than one distinct route, the Chamagudao once stretched for al