Detroit Salt Mine: The hidden gem beneath our city.

By: Kurt Buesching | October 8, 2012

I’ve always been fascinated with salt. Laugh away, but it has an incredible history! Civilizations expanded and progressed in the quest for this amazing spice. Opposing militaries used it as a weapon of war, salting the fields to spoil land for crops. In ancient China, they used salt as currency. There isn’t a point in time when salt wasn’t important.

This is why it’s so exciting to me that Detroit has a massive working salt mine that stretches 1,500 acres from Dearborn to Allen Park. The mine shaft itself is 1,160 feet straight down and there are more than 100 miles of roads connecting the different areas of the mines. It’s an entire city beneath a city!

Rock salt was discovered in Detroit in 1895, but it wasn’t until 1906 that the Detroit Salt and Manufacturing Company began the arduous task of digging a shaft to create a mine. Despite many challenges, a bankruptcy and business reorganization, the shaft was completed by the newly named Detroit Salt Company.

In 1912, under the name Detroit Rock Salt Company, crews began work on a second salt bed. The new operation improved productivity and rock salt purity, which caught the eye of the International Salt Company who acquired Detroit Rock Salt in order to keep their edge on the marketplace. By 1914, crews began to utilize “modern” technology in the form of electric power, mechanical shovels and electric trains to help keep up with production needs, to the point that it was producing up to 8,000 tons of rock salt each month.

With the demand for salt steadily increasing, the company recognized a need for a larger, second shaft and began to dig in 1922. By 1925, crews had completed the work and began using it to haul more rock salt to the surface. Crews continued to mine the rock salt until 1983 when production costs began to exceed salt prices, and International Salt halted operations. In 1997, Detroit Salt Company purchased the mine and began production again, which continues to this day.

And while it’s awesome to think that this mine has been operating virtually non-stop for the past 100 years, without fatalities or a collapse, there are other facts about the mine that are even more mind-blowing!

For as large as the mine is, you can imagine that the equipment needed to blast the salt and haul it around needs to be just as large. And getting it down those narrow shafts isn’t an easy feat. Typically, the equipment like trucks, machinery and jeeps, are disassembled, lowered down piece by piece and reassembled in the mine’s shop area. Then, once down in the mine, it stays there.

Another interesting fact is that if the mine shaft were a building, it would be second only to the Empire State Building which is 1260 feet tall, compared to the shaft’s “measly” 1160 feet. And, thanks to the depth, the temperature stays about 60 degrees year round. Perfect weather, if you can get over the fact there’s no sun.

But the greatest thing I find about the salt mine is the fact that you’d never know how big the mine is or how much goes on under our feet on a daily basis just by looking at the entrance to the mine. It’s sort of a metaphor for Detroit, isn’t it? There’s more to us going on than you think. Don’t take our city at face value. Sometimes you gotta dig a little deeper to get to the stuff that matters. And in this case, it’s salt.

To see some really great images, The Detroit News has an incredible archive of images from the mines first days, as does Environmental Graffiti.