This paper aims to investigate the root of ongoing conflict between China and Tibetan regions for independence. By using the data collected from waves of protests in 2008 across Tibetan regions in China, it investigates the extent to which the physical Han Chinese presence led to political mobilization. The findings show that regions with stronger presence of Han population witnessed less protests, suggesting powerful influence of geography and ethnic integration on the spread of Tibetan Buddhism and independence movement over a long period of time. In order to explain the settlement patterns of Han Chinese in Tibet, the paper exploits the physiological differences between Tibetans and Han Chinese in their abilities to adapt to high altitudes.