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Salt City

Detroit's salt mines are called "Salt City" because of their size and the fact that they span underneath a major part of Detroit, itself.

The area covered by the mine is enormous

and deep

Detroit’s salt mines are like an underground city in the ground beneath the city. It is a massive expanse of 1,500 acres and over 100 miles of roads 1,200 feet under beneath the city's surface. It stretches from Dearborn, located in the northwest of Detroit’s metropolitan area to Allen Park in the southwest.

How did all that salt get under the city of Detroit in the first place? For an answer to that question, we have to go back about 400 million years when the first humans weren’t even a speck on the horizon. An area today known as the Michigan Basin was then separated from the ocean and kept sinking lower and lower into the Earth. Salty ocean water kept pouring into it until gradually, the ocean receded, leaving the water to evaporate and huge salt deposits to form.

Then, through glacial activity, the Niagara Escarpment formed – a basalt rock area including the whole state of Michigan and beyond – and buried the salt layer. Today, the Great Lakes rest on the basalt rock and the salt layer, some 1200 feet below the surface.

  

The Detroit area salt deposit is the largest in the world – some 71 trillion tons of unmined salt remain according to some estimates, even after a 73 years of mining, in which around 8,000 tons of salt were removed from the mind each month.

One might say. "Salt. Big deal. It’s not oil and not gold, so who cares?" True, but there was a time, even in the surprisingly recent past, when salt was a precious commodity and as valuable as gold. In early China, for example, salt coins were a popular means of payment and salt cakes served the same purpose in the Mediterranean. The Romans often paid their soldiers in salt – that’s why we’re still using the term salary today from Latin 'sal' – salt. There were times when salt was so expensive that those who possessed it would refust to eat it. To eat it was to destroy their wealth.

Tons of salt await their trip to the surface

So even a single lump of salt like one shown in the above picture would be worth more than a man could earn in a lifetime.

Mine workers

Unfortunately, the people who got rich were not the ones who did the actual mining, moving the salt to the surface and getting it ready to ship.

As one can imagine, life was tough underground and often what went down, stayed down. Donkeys brought below ground to work usually stayed underground, where they died a no doubt early death. All the equipment once brought down also stayed there – getting it through the narrow shaft opening (just 6 x 6 ft) was just too painful as it had to be taken down in pieces and assembled in the mine's workshops.

Salt mine workers would drill deep holes with large, heavy pneumatic drills, stuff dynamite into the holes and set it off. There was always a question as to whether it could cause any of the 1,200 feet of ground above it to come crashing down onto them. Because they were in a space where the sound of the explosions could not dissipate, but only travel down the tunnels toward them, hearing loss was not uncommon.

Yet, it was a good paying job - as jobs and pay went at the time - and it was also a clean and bug-and rodent-free work environment, which was extremely rare for work environments at the time. One worker, Joel Payton, remembered in later years: “One reason we didn't have any rats in our Detroit mine is because the rats would have nothing to eat except the leavings of our lunch pails." He added, "And by the way, not only are there no rats or cockroaches or other living creatures in our mine, but also no remains of living things from past ages.”

Operations went on until 1983 when falling margins and salt prices made production altogether unprofitable. The salt mine remained unused until in 1997 the Detroit Salt Company LLC purchased it. The company began salt production again with modern equipment, electric lighting, and much better work conditions in the fall of 1998 and currently provides not just table salt, but is one of the major producers of road deicing salt and salt for water softeners in the USA.

FEEDBACK MAP

If you got impressions for which this feedback is insufficient, please take a look at the following web sites for more:

Environmental Graffiti
Detroit Salt website
Atlas Obscura
Michigan Pictures