Metropolitan Mining

“Some 1,200 feet beneath the streets of Detroit, under the north end of Allen Park, Dearborn’s Rouge complex and most of Melvindale, runs 100 miles of subterranean roads over an area of more than 1,500 acres. It is the Detroit Salt Mine and as a Detroit industry it is older then automobiles. As a geological entity, this salt deposit is older even than the dinosaurs.” (Via Atlas Obscura)

According to John D. Nystuen at the University of Michigan, “The Detroit salt mine was started 1906 and finally closed operations in 1985 after millions of tons of salt had been removed. The work created extensive man-made caverns under the city that remain today. The Detroit mine has a rather complex shape that is intriguing to geographers and that calls for some explanation.” The map below shows the complex shape of the mine.

I highly recommend reading all of Metropolitan Mining: Institutional and Scale Effects on the Salt Mines of Detroit, which gives a good history to an industry unknown to most people. Whether it’s salt mining, underground transportation or public space, I’m fascinated with subterranean activity. In fact, these salt mines remind me a lot of a recent post of mine on speleotherapy - the therapeutic use of salt mines, caves or other forms of exposure to salt air.