n the 1970s,a group of herders drove their cattle and sheep 300 kilometers northward from Shantsa County in Nagqu to the no-m an’s grassland.They did this because their livestock had low levels of grass available for grazing,and this was the first modern-age instance of human(and animal)migration.It was here that they built Tsonyi County,the highest county in all of China,sitting at over 5,000 meters above sea level.