Báimǎguān

Báimǎguān stands in the hills about thirty kilometres north of Kang County’s later seat, at present-day Yúntái. The pass controls mountain roads between Longnan, southern Shaanxi and northern Sichuan. Deep valleys, forested ridges and narrow river terraces made every crossing a strategic point. Its name links the fortification with the Baima Di peoples remembered in the region, whose communities long occupied the surrounding highlands.

Ming and Qing officials used the pass to control movement between Shaanxi and Sichuan. In 1729 the Zhili Department of Jiezhou established a subprefect at Báimǎguān; in 1736 it became a separate Báimǎguān subprefecture. Soldiers, couriers and merchants passed through a settlement that still lacked a complete stone wall.

Farming families occupied the surrounding valleys, growing grain and gathering forest products. Upland roads joined the pass with broader Sichuan–Gansu trade, while garrisons and couriers gave central authorities a foothold in the broken border country. Báimǎguān was chiefly a mountain crossing, garrison and administrative station. Its history is tied to the pass rather than to the wider county as a whole.