More than a millennium ago, salt traders based in Tsakha township, Ngari prefecture of Xizang autonomous region, would extract natural salt from local salt lakes and transport it by loading it onto yaks and sheep.

They herded the animals while traveling long distances to places like Pulan county of Ngari prefecture, Shigatse city of Xizang, and even across borders to India and Nepal.

During each journey that took two to three months and involved grueling hardships, the traders bartered salt for essential goods such as barley, brick tea, and cloth.

The 74-year-old Tsering Samdrub began working in the salt trade at the age of 16 or 17. He recalled using primitive tools, such as ram horns, to shovel salt from the lake, then loading it onto Tibetan sheep to carry it to Pulan for trade.