Michigan’s Massive Salt Reserves

By James Donahue

To fly over the State of Michigan today one would never guess that the entire state hides one of the largest deposits of natural salt to be found anywhere. The state has long been known as an industrial and agricultural center. Before this it was known for the great stands of timber, the mining of iron ore and copper and the great schools of fish once scooped from the lakes.

Deep in the ground, almost everywhere men drilled for water, if the drill bits went too deep they always hit salt water. Miners along the Lake Huron shoreline, from White Rock south to Port Huron and Detroit, found thick veins of salt that were turned into yet another profitable business enterprise.

One of the best known names in cooking salt is the Diamond Crystal Salt Co., which began operations in St. Clair County in 1866. Charles and Franklin Moore, Justin Whiting and Mark Hopkins founded what began as the St. Clair Rock Salt Company, which later became the Diamond Crystal Salt Company. It is now owned by Cargill and still operating as a source not only of table salt but of road salt used by county road crews for dealing with snow and ice.

There were several other salt mine enterprises in Michigan over the years but the largest was probably the Detroit Salt and Manufacturing Company, founded in 1906 after salt was discovered 1,200 under the city. The company later became the Watkins Salt Company, then the International Salt Company, and eventually the Detroit Salt Company LLC. This mine became such a large enterprise it produced about 8,000 tons of rock salt a month, mostly used for road salt and brine

The Detroit mine became such a big operation the workers carved out more than 100 miles of tunnels and large rooms with ceilings supported by pillars of rock salt spanning an estimated 1,500 acres from Dearborn to Allen Park. In the old days mules were used to pull cars filled with salt along railroad tracks. Later electric engines were used. The mine operated like that until the depression years closed it down for a few years. It is still operating but at a smaller pace today.

Thus there is virtually a secret complex of man-made tunnels and caverns in existence amid the thick salt beds, especially along the Detroit River and the Lake Huron coast. They are so deep in the ground that most people are not aware of their existence.

Because there is so much salt deep in the ground, Michigan has been a major world producer of salt used both in the kitchen and by road crews. So much salt is used in battling snow and ice on Michigan roads that the state is known for its fleet of rusting cars and trucks. In my youth, after I began driving Michigan roads, the cars we drove rarely operated for 100,000 miles before we were forced to junk them. Overhauling the engines sometimes wasn’t worth the trouble because the vehicle’s bodies were so rusted by the time the piston rings needed to be replaced.

The development of special salt resistant sprays and non-rusting auto body parts, coupled with longer life engines, however, solved a lot of these problems. Vehicles now are better equipped to deal with Michigan road salts and last for years if the owners take the time to wash them down regularly during those harsh winter months.

So Michigan is located in about the heart of the North American continent. The state is surrounded by fresh water lakes. So the mystery is why so much salt is found that deep in the ground.

Geologists explain that the state once was identified as the Michigan Basin, a large sunken part of the landscape that was part of the great oceans and filled with salt water. But as the world changed, the oceans receded and the water in the great basin evaporated, great deposits of salt were left behind.

All of this happened an estimated 400 million years ago so there was a lot of time for things to shift and move around on this old planet.