Monday, June 2, 2014

Descend half-a-mile underground for walk through iron ore mine

Soudan Underground Iron Ore Mine.
Photo courtesy of Minnesota DNR.

Minnesota's oldest mine
now a tourist attraction

Day hikers can explore tunnels a half-mile underground at Minnesota’s oldest iron ore mine.

The unique historic tour at Soudan Underground Iron Ore Mine State Park takes visitors through 2.7 billion years of geological history. For the claustrophobic, alternative nature trails can be found on the surface.

No state park vehicle permit is needed at Soudan Mine, but there is a fee for the mine tours, which typically run Memorial Day through September.

Ancient processes
To reach the take park, take U.S. Hwy. 169 to Soudan. Once in town, head north onto Main Street. Turn west on McKinley Park Road and take the first right/north into the park (Note that this is the summer entrance.). Park in the lots beyond the Breitung Pit monument and enter the interpretive center for tickets and the mine entrance.

Before entering the mine, visitors must walk across mats designed to remove spores from their shoe bottoms. Spores tramped in by people are a common way of spreading a fungus that causes white-nose syndrome, which is fatal to hibernating bats.

Next hikers are given a hard hat and enter a cage – that’s miner talk for an elevator – to head down 2,341 feet in a 3-minute ride to the 27th level. From there, you load aboard a rail car and descend even deeper for a 90-minute tour. While it’s not a hike in the truest sense of the word, there are plenty of opportunities to walk around and explore.

Hundreds of millions of years ago when this part of Minnesota was covered by a sea, volcanoes deposited low-grade ore onto the sea floor. As the sea floor rose into mountain tops over time, weathering concentrated the ore into rich hematite, which is the mineral form of iron oxide. Glaciers during the last age exposed one of those hematite veins at Soudan.

Mysteries of the universe
After several geological expeditions to the area, the Soudan vein was discovered, and mining began in the early 1880s. Most of the open pit mines at the state park were dug by hand until the underground mine was opened in the 1890s. Eventually, new mining techniques made the Soudan operation too costly to continue operation, so the United States Steel Corporation closed it in 1962 and donated the site to Minnesota for a state park. During the mine’s lifetime, 15.5 million tons of ore were removed for steel production.

The mine today serves as a physics laboratory. Two projects there aim to understand the nature of neutrinos and of dark matter. A tour is offered for the physics lab as well.

Above ground, combine the historic tour with the 0.2-mile West Tower Mine Trail visitors. Among the buildings you can explore are the dry house, the frill shop, the crusher house, and the engine house. A boardwalk takes you past one of the park’s deepest open pit mines.

The mine is 50 degrees no matter the season, so always wear a warm jacket during the historic tour. Shoes with good traction also are recommended.

Read more about day hiking Northeast Minnesota in my Headin’ to the Cabin: Day Hiking Trails of Northeast Minnesota guidebook.