On a crisp autumn morning in 1937, Peng Gui’e stood at Mong Mong to reclaim a mission compound. For Peng, a native intellectual and son of Yunnan, this moment was far more than a simple property transfer. The modest wooden houses once occupied by American missionaries would soon become classrooms for Chinese teachers-in-training. This transformation symbolized the triumph of sovereignty and the assertion of state authority in a borderland long marked by instability and fragile state presence. Where missionaries had once planted their stakes, Peng and his colleagues now raised the Chinese flag.