What's Under Your Feet: The Gypsum Mines
Near Grand Rapids, Michigan
Right now, underneath parts of this city and the suburb of Wyoming just to the south, there is a network of tunnels carved out of solid gypsum deposits that sit roughly one hundred feet below the surface. Grand Rapids was, for a century, one of the gypsum capitals of America, and almost nobody driving through today knows it.
Gypsum was first discovered near what is now called Plaster Creek by a Native American trapper in eighteen twenty-seven. Michigan's first state geologist, Douglass Houghton, confirmed the deposit in eighteen thirty-eight. By eighteen forty-one, the first quarry and mill were operating on the bank of Plaster Creek, crushing the soft white rock into the plaster of Paris used in buildings across the eastern United States. The industry is the reason nearby Paris, Michigan, carries its name.
As the surface deposits ran out, the mines went underground. By eighteen ninety-eight, William Powers had begun construction of a mine shaft that burrowed one hundred feet beneath the bed of the Grand River, with tunnels extending outward for acres beneath downtown. Workers descended in cages, blasted the gypsum with controlled charges, and hauled tons of raw material to the surface daily.
The mines operated for over a century. The last major operation, the Domtar Mine, closed in nineteen ninety-eight. Today the tunnels do not sit empty. Sections have been converted into a remarkable use: underground dry storage. At temperatures that remain constant year round and with almost no humidity, the caves hold microfilm records, legal documents, and archival material for businesses and institutions across the region. Seventy percent of Michigan's county legal records are stored down there.
Plaster Creek still runs through the city, a small reminder of an industry that once made the city famous for something besides furniture.
