At Soudan Underground Mine State Park, where the above-ground temperature can fluctuate from 30-below to 90 degrees Fahrenheit, it's always a cool 50 degrees 2,341 feet below the surface. A tour of the subterranean labyrinth near Tower, Minn., brings you down to the 27th level of Minnesota's oldest, richest and deepest iron mine. Recently I joined 34 other visitors for this 90-minute journey to the center of the Earth.
As our guide showed us how to adjust the blue and yellow helmets everyone is required to wear, I saw her eyes sweeping the crowd to ensure that everyone had the proper footwear to descend into the cavernous pit: It's clear that flip-flops won't cut it. The rustic, 90-foot steel tower known as the headframe sits at ground level above shaft No. 8. As we waited for our ride, we heard a series of beeps before the elevator cables began swaying, signifying the elevator's rise to the surface.
We got in, the door closed on the metal "cage" and we began our 2½-minute, 10-mile-per-hour descent to the mine's lowest level.
Claustrophobics, be warned: The ride is loud and dark. Unlike conventional elevators, this one doesn't go straight down — it descends nearly three-quarters of a mile at an angle to parallel the ore formation, so when you reach the bottom, you're actually 500 feet north of where you started.
As we were directed to step into metal, four-person tram cars, I looked up to see a wooden sign that read: "level no. 27. 2341 feet below the surface. 689 feet below sea level."
Condensation covered the mine walls, and the scent of damp rock filled my nostrils as I sat down on the cold metal seat. (No, my cellphone didn't work this far underground. I checked.) Uncovered fluorescent bulbs and a series of camera flashes lit the path as the tram jolted us through the tunnel.
Taking care not to slip on the loose, wet rock, we gingerly made our way over to a 38-step spiral staircase leading up to the Montana stope. ("Stope" is a Cornish mining term meaning "step.") Although the metal staircase is so steep that we needed to proceed single file — and everyone used the handrail — we were reminded that the miners had to walk in the dark through the long tunnel and navigate up through the opening on a wooden ladder. "We've made it fancy for you," our tour guide joked.
Miners would work from above and drop the iron down holes called ore raises because it was so heavy. At 70 percent iron, the Soudan rock is some of the purest in the world: One cubic foot weighs 325 pounds. A small sample was passed around and even though it was only the size of a small Frisbee, I needed both hands to hold it up.
