Day 10: Minnesota Iron Mining Country

After a thunderstorm dropped heavy rains on us last night, we had perfect weather today for an underground mine tour: a high of 46 degrees, breezy, and occasional light rain. Before we went underground, though, we took a few photos in Grand Rapids (MN) and stopped at an open pit mine near Hibbing. The Hull Rust Mahoning Mine is the world's largest open pit iron mine, and when I first saw it, I immediately thought, this must be the "Grand Canyon of the North." I found out later that's exactly what it's been called. Frank Hibbing first began mining here in 1892, so the pit has been over 120 years in the making. Its maximum length is 7.5 miles and maximum width 3.5 miles. It is 800 feet deep at its deepest point. Each day, a train with 105 railroad cars full of taconite (the iron ore being mined here, which is about 37% iron) leaves the mine. The mining is only expected to last about another ten years at this mine, and then it will be allowed to fill with water, which will create a lake 500 feet deep and only take about 2 1/2 years to fill.  (As if they need another lake in these parts! Minnesota has over 11,200 lakes of at least ten acres in area.) There are a total of eight open pit iron mines in a row in this part of the Mesabi Range. The iron ore belt stretches some 90 miles from near Hibbing northeast to Ely, MN. Another smaller extension is located in the upper peninsula of Michigan.

Just 20 miles southwest of Ely, we toured another mine at Soudan Underground Mine State Park. This is the oldest and deepest iron ore mine in Minnesota. Mining began in 1882, eventually reaching a depth of 2,341 feet before mining ceased in 1962. The hematite here is a higher grade iron ore than the taconite being mined near Hibbing (up to 65-70% iron in the ore), but is more expensive to remove.

The tour itself is impressive (and definitely not recommended for anyone who is the slightest bit claustrophobic!). They packed 12 of us in about a 3 foot wide by 6 foot deep "cage" that is lowered to the bottom of the mine (all 2,341 feet of it!) by cables operated by a hoist system. The ride down only takes about three minutes. (It just seems longer.) Once down, we rode on small cars on the rails that were used to haul taconite until the mine closed. We went about 3/4 of a mile into a tunnel, then got out and climbed a spiral staircase up to a level where they actually removed the ore. It was a fascinating and informative tour and only took an hour and a half total.

I have always wanted to see the Mesabi Range and the iron belt in MN and learn firsthand about the mining operations here, since iron ore was so crucial in the economic development of our country, especially in transportation (and nearly all the iron ore in the U.S. comes from this region). Iron and steel produced from iron ore drove early industrialization and have been used for railroads, autos, farm and factory machinery, tools, and all manner of other products indispensable to the growth of the country.

We ended our day in Silver Bay, on the shores of Lake Superior. Silver Bay has a taconite processing plant which refines the ore (which comes in from nearby mines by train) into pellets that are then shipped via the Great Lakes to steel mills in areas such as Cleveland, Ohio (located closer to the major deposits of coal, a major energy source and the other major raw material needed to produce steel).

Downtown Hibbing, MN (pop, 16,500).

Photos don't really capture the absolute immensity of the Hull Rust Mahoning Mine.

This panorama of the mine only shows about half of it.

The taconite is the dark gray layers diping to the right in the center of this photo. That's the pay dirt!

The trucks currently working at the mine can haul 240 tons of material. The one has just dumped a load of overburden being removed from above a layer of taconite higher up in the mine.

This was actually a "small" truck, only capable of hauling 170 tons of material.

The mine was like a wind tunnel, with winds gusting at the viewpoint at easily 40 or more mph.

View looking west from near entrance to Soudan Underground Mine. Northeastern Minnesota is densely covered by a mixed forest of needleleaf evergreen and broadleaf deciduous trees.

Bedrock of the Canadian Shield, which was scoured by continental ice sheets. In many areas it has only a thin veneer of soil (but usually enough to support trees).

Log truck ready to haul wood to a paper mill, such as the one below at Grand Rapids, MN.

Side view of the "cage" in which we were lowered down into the Soudan Underground Mine.

Nearly half a mile underground!

Bands of hematite (high grade iron ore).

One of many rivers winding its way across the Canadian Shield.

Moss. lichens, and plants growing on rocks of the Canadian Shield.