In ancient times, there were three natural salt springs in eastern Chongqing and western Hubei-Baoyuan Mountain Salt Spring in Wuxi (Daning Salt Field), Funiu Mountain Salt Spring in Yushan Town of Pengshui and Qingjiang Salt Spring in Changyang County, Hubei Province. Baoyuan Mountain is the earliest known salt spring in China, which has a history of 5,000 years and is still flowing today. In ancient times, before the invention of deep well brine extraction technology, the natural salt spring of the Three Gorges was the earliest source of salt supply in inland areas. The Pakistanis control this precious resource. Wuxi Baoyuanshan Salt Spring (Daning Salt Field), a poor place with a vast territory and a sparse population, was once the earliest rich reservoir in ancient China. The whole saltworks is five miles long, and people come and go on the field, and all rivers contend for currents, forming the spectacle of "thousand stoves and smoke". The whole Hanzhong basin, the two lakes basin, the Sichuan basin and the western Hubei region should be supplied by Daning saltworks. Ningchang town is in Yanba.

It was a big city in ancient times. At its peak, it became a small town with a population of 14000, where business travelers from all directions gathered. About 654.38 million people make a living from salt industry. Daning Salt Field is surrounded by mountains, and the locals say that apes are also difficult to climb. Witch salt first came out of Sichuan, and the industrious Ba people crossed the back mountain of Qinling Mountain along the narrow and steep mountain road. The Ba people have opened up a 4,000-mile Yanshan Road. Witch salt was transported to the mountain road in western Hubei and southern Shaanxi. Among the mountains, there are already eight salt roads, which the locals call "Qin Chu Avenue". At the same time, it also opened up a 400-mile salt water transportation road. Daning River is an important tributary of the middle and upper reaches of the Yangtze River. Witch salt is extended to Wushan and then transported to all parts of the country from the lower or upper reaches of the Yangtze River. The third is the 300-mile salt diversion plank road. Along the banks of Daning River, Ba people chiseled a plank road about 300 miles long and rolled Wuxi Salt Spring along Daning River to Wushan. Far away from Cuba, people monopolize the salt necessary for human beings and call it "salt bar".