This salt bed spreads over 170,000 square miles under Michigan, Ontario, Ohio, Pennsylvania, New York and West Virginia. A salt mine worker drills holes in the salt wall in preparation for the dynamite blasting. Some estimates suggest that there is enough salt in the Metro Detroit underground to last 70 million years. Michigan's Indian tribes used salt springs long before the white man came. In 1841, Douglas Houghton supervised the sinking of the state's first salt well in central Michigan, the beginning of a series of borings that led to the establishment of the Dow Chemical Company and the discovery of the central Michigan oil and gas fields.
Salts are among the most important chemical compounds.
They are used in making many industrial and agricultural chemicals. Sodium chloride is used in making chemicals needed in the manufacture of rayon, soap, and other products. Salt ammonium nitrate is used in fertilizers. Some metals, including sodium and potassium are extracted from salts. Salt mining in Detroit began in 1896 with the sinking of an 1,100 foot shaft, but the investors went broke.