It is hard to believe that an area on the mountain summit reaching up to the cloud in Bo Kluea district has been an important salt production venue from ancient times. Nan has been a large exporting source of rock salt in the north. Salt was a product exchanging with other things that the community could not produce by themselves. The exchange was conducted with the caravan of the Haw People from Yunnan, Guangxi and other provinces in China by taking the route from Xishuangbanna, Shan State to Chiang Rai, Chiang Mai, Nan, Mueang Sa (Wiang Sa District nowadays) and Phrae, as well as, the Thai Khoen sellers from Keng Tung and the Thai Lue cow traders from Tha Wang Pha district. In the past, rulers in the Northern administrative circle got a part from the salt levy apart from other fees and fines. Phraya Tilokkarat of Chiang Mai also led the troops to invade Nan with an aim to possess the salt pits which were a significant military factor during that time.
There are 2 important salt production venues in Nan. The first one is in the Wa River watershed area, consisting of 2 large pits, while the second one is at the Nan River watershed area, where there are 5 large pits and many tiny ones. At present, the locals still boil the salt by using the traditional method. Saline water will be brought from the pits and pass along the bamboo sticks to the storage ponds. Then, it will be boiled in large woks until the water evaporates, leaving only the dry salt. The salt will be put into bags and sold in front of the houses. Salt of Nan does not contain iodine like that from the sea. Therefore, iodine has to be added before offering to consumers.
The Rock Salt Pits are 80 kilometres from Mueang Nan. Apart from agriculture and farming, people of Bo Kluea district also produce salt. The source of the rock salt is on the mountain. (The salt pits are usually closed during Buddhist Lent due to the rainy season.)