The Whiskey Island salt mine, owned by food giant Cargill, helps supply road salt across the Northeast and Great Lakes due to a colder, snowier-than-usual winter that has driven demand. The mine, one of the world's largest, produces 3 million to 4 million tons annually, but falls short of demand in particularly harsh winters. It is located 1,800 feet underground and operates year-round. Despite the return of harsher conditions across the Eastern U.S., there is still decades of salt left to be extracted.