This is in Qinghai province, not Tibet. For centuries it was border/battle ground among various Chinese dynasties, Tibetans, and Mongols, but it has been part of China continuously since the early 18th Century. Han Chinese are the majority ethnic group (~54%), with Tibetans the largest of several ethnic minorities. Much of the province's population is in eastern Qinghai Province, with the largest city (by far) being the capital, Xining.