During the Chinese People's War of Resistance against Japanese Aggression (1931-1945), the Lanzhou people have used sheepskin rafts to transport gasoline and other materials to Chongqing.

In 1941, the major transportation artery in Southwest China was cut off by Japanese invaders, and the transportation cost from Yumen Oil Mine to Chongqing was high due to complex terrains. The sheepskin raft solved the urgent need and became the pride of Lanzhou people.