All through the Kham and Amdo regions of Tibet you find yaks grazing on the vast grasslands. These grasslands are sparsely populated. About the only people you will find are nomads living in tents. The elevation of a large percentage of these grasslands is well over 4000m. Little vegatation grows. Trees are nowhere to be found. In these remote areas of greater Tibet yaks are the only thing in abundance. Three of Asia's longest rivers flow through these remote grassland areas. The Mekong River, Yellow River and Yangtze River flow down from their high elevation sources in the Kham region of Tibet down to the grassland areas before flowing out across China and southeast Asia.