Way back when, there was an ill fated gold rush in the northern region of Minnesota which netted virtually no gold but did reveal large deposits of very rich high quality iron ore. This ore was needed to make steel because the steel making process was done in open hearth furnaces and they didn't then have the ability to use lesser grade ore. This was also before the mining industry had developed Taconite pellets. The high grade ore was something like 60% pure iron and this was a boon to mining in the area for the time before steel-making could be done at higher temperatures (in blast furnaces?) with less pure ore. The Soudan Mine operated from 1882, going underground in 1892, until 1962 when the mine shut down and was given to the state.
the above were taken from the brochure for the mine tours- now my own photos of the "adventure"-
TB awaits the elevator to lower us a half mile underground to level 27...
the lift mechanism for the elevator in the shaft-
amazingly- one guy handles every lowering and raising of the elevator into and out of the shaft - including the short drop for the double deck elevator cabins... all on the signals from the buzzer! Jeez - doesn't that remind you of Dirty Harry? Did I hear four buzzes or only three? How nerve wracking that job would be!
From here we went back to Ely for lunch at a small place in town- and then went for a snack at DQ - we would be headed back to Soudan to visit the High Energy Physics Lab in just a couple of hours - but that will be another post...
so back next time with mind bending physics and a brief stop in Tower MN (coldest recorded temperature in the lower 48!) so keep on coming back for more excitement! LOL