https://www.chinadaily.com.cn/travel/2012-11/15/content_1593...
"Sheepskin rafts can be traced back to the Han Dynasty (206 BC-AD 220), when soldiers used them to ferry men and goods during wars. Local residents in Lanzhou used them to shuttle passengers, fresh fruits and vegetables across the river."
Sheepskin raft becomes popular for tourists to sightsee along Yellow River in Gansu
http://www.xinhuanet.com/english/2019-05/31/c_138105617_9.ht...