Eminem isn’t the only thing salty to come out of Detroit…

Detroit, Michigan USA is known by a lot of names. Mo-town. The Motor City. The Cautionary Tale of Auto Industry Decline Meets Institutional Government Corruption. The D (ed. note: No, really). The Birthplace of the Coney Dog (ed. note: that’s another topic for another day).

One more name it might deserve is Salt City, USA. You see, nearly a quarter mile BENEATH the gritty streets of Detroit are an entirely different collection of dirty boulevards…ones made up entirely of salt that is more than 400 million years old.

And that’s where our story begins. Back in the Devonian period, the chunk of real estate that eventually became Detroit was under water, part of mid-west America’s cycle of being covered in inland seas and then drying out, which continued for a couple hundred million years. This cycle of wet-dry-wet-dry left tremendous deposits of evaporated seawater on the remaining land, which means salt. Loads and loads of salt.

devonian map

Looks like a crab claw has grabbed a mitten.


In pre-colonial times, native american tribes in the area, extracted the salt from salt springs, but it wasn’t until the early twentieth century that companies first began looking at commercially extracting the salt. Only one problem though – the salt could only be found underground. Like WAY underground. More than 1,000 feet down in fact. So in 1910, the Detroit Salt and Manufacturing Company completed a shaft down to the luscious and tender salt (ed.note: those are not good words to describe salt. Neither is “succulent” now that we think of it. Pretty much just go with “salty”).

The shaft down to the salt mine was reportedly so narrow that all machinery sent down

mine map

Image credit: Detroit Salt Company

had to be sent down in pieces and reassembled on the mine floor and and equipment that was brought down was left to remain in the mine for perpetuity since it was impossible to bring anything but salt and miners back up. The same went for the donkeys originally sent down before powered mining gear existed. (ed. note: presumably he means that they were left down there forever, rather than sent down in pieces and then reassembled. Because, eww).
Over the past century, ownership in the salt mine below has changed hands several times, but the currently very active mine is currently owned by the Kissner Group. Although the salt mined beneath Detroit is no longer used for human consumption, tons of the stuff are still mined for use as road salt each year, with an estimated 71 TRILLION tons left to be mined.

So, the next time someone tells you that Detroit Rock City is a decaying post-industrial wasteland, you can tell them a very good pun about rock salt while complimenting them on their spot-on analysis of Detroit (ed. note: For realsies though, Detroit has been undergoing a renaissance over the past several years and downtown Detroit has become a destination for travelers again and Detroit is the ONLY city in the US where all four major sports franchises are all houses within a four-block area. If you get the chance – check it out.)

For more information, check out the history of Detroit Salt.