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 almost 1,400 miles (2350 km) a conduit along which the historic trade between the mighty Chinese empire and the nomadic Tibetans linked remote villages and ethnic groups. The Chinese military needed strong horses for their wars against Mongol invaders from the north, and the fiercely religious Tibetans desired tea both for sacred rituals and sustenance. Once tea was introduced into Tibet around the 10th century, demand for it grew. Tea soon became a staple for Tibetans, especially when combined with their other staple, yak butter. But with Tibet's extreme temperatures and altitudes, tea cultivation on a large scale was impossible. This set the stage for the tea-horse trade, which, by the 11th century, flourished along the Chamagudao, continuing until the 1950s. AUTHOR: Michael Yamashita was born in San Francisco, California, and grew up in Montclair, New Jersey, in suburban New York City. He graduated from Connecticut's Wesleyan University in 1971 with a degree in Asian studies and went on to spend seven years in Asia. While he had no formal instruction in photography, Yamashita managed to turn what began as a hobby into a career that combined his two passions-photography and travel. A regular contributor to National Geographic Magazine since 1979, his assignments have focused on Asia, but he has covered such wide-ranging locations as Somalia and Sudan, England and Ireland, New Guinea and New Jersey. Fluent in Japanese, he has covered the length of Japan, the country of his parents. Yamashita's particular specialty has been following the "paths" of both man and landscape, resulting in stories on Marco Polo, the Japanese poet Basho, the Chinese explorer Zheng He, the Mekong River and the Great Wall. The Ghost Fleet, a feature film narrated by Yamashita and based on his article on the world's largest wooden armada and its admiral Zheng He, won the Best Historical Documentary prize at the New York International Film Festival. Yamashita's sister was an accomplished amateur photographer who sparked his own interest in the craft. Elizabeth Bibb first moved to New York to attend Columbia University Graduate School of Journalism and has since lived uptown, downtown and in-between. She is a writer and editor who works in both magazine and book publishing. Bibb is a frequent collaborator with her husband, photographer Michael Yamashita. She lives with her husband and daughter in Murray Hill in Manhattan, as well as in rural New Jersey. 185 colour photographs