Geologists put the age of rock-salt found in Khewra at about 600 million years. In geological timescale this time period is called Precambrian. It is said that discovery of rock salt in Khewra area dates back to as early as circa 326 BC. According to a legend, the army of Alexander the great was resting in Khewra area after a battle with Raja Porus. Some horses of Alexander’s army were then seen licking rock salt in the area. Somebody from Alexander’s army noted down the incident in his ledger or diary and hence? We came to know that salt was discovered? Here circa 326 BC.? History is however silent? On which language this incident was recorded in (Greek?) or where is that diary now. But since those days people in the area continued to collect salt from the out crops of salt seams that were exposed at the hill surface.

It is the only rock we eat. Its Latin name, salax, is the root of the English words "salacious" and "salary," placing it at the heart of two of humanity’s most basic and enduring preoccupations: sex and money. Indeed, it has been used both as a medium of exchange and as a guard against impotence, although its most common uses today are as an ingredient in plastic and as a method of ridding highways of winter snow and ice.

These salt ranges are located at the foothills, between the valleys of the Indus, in the northern part of the Punjab region of Pakistan. It derives its name from extensive deposits of Crystal salt, which are one of the richest salt fields in the world; they are of Precambrian age. The salt range is more than 1,600 feet (490 m) in thickness and spread approximately 186 miles (300 km) beneath the Karakoram Range and the Great Himalayas of Pakistan. Home to the world's greatest masses of high mountains, nine of the world's fourteen 8,000-meter peaks are located here including
K-2. The world’s second highest mountain after the Mount Everest.