Detroit salt mine
United States · built 1910
The Detroit salt mine is a salt mine located 1,100 ft (340 m) below Detroit, Michigan. The mine opened in 1910 and covers 1,500 acres (610 ha) underground. In the beginning, the leather and food industries were the primary customers. Today, road deicing salt is the primary product.
Mine data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).