Last Open Pit Mine Digs Its Own Grave

AURORA, Minn. —  Trucks the size of houses rumble in and out of the Donora mining pit with sandbox simplicity.

With each round trip to a nearby processing plant, they bring North America’s last working open pit mine of high-grade natural iron ore about 100 tons closer to extinction.

“At one time we thought the natural ore on the Mesabi Range was going to last forever,” said G.B. Morey, chief geologist for the Minnesota Geological Survey.

That was in the 1890s, when the nation’s largest deposits of moist black and blue ore were being discovered on the Mesabi, Vermilion and Cuyuna ranges in northeastern Minnesota. About 2.82 billion tons and two world wars later, the Donora pit just east of Aurora at the McKinley Extension Mine is all that is left.

‘End of an Era’

There are other natural ore deposits scattered around the Great Lakes, in Canada and the western United States, but none that can be profitably mined with today’s technology, Morey said. Abundant taconite, a flint-like rock containing a low-grade iron ore that is extracted and converted into pellets, has replaced it as the main source for steel.

“You can’t ever say it’s dead,” Morey said of natural iron ore mining. “But it’s the end of an era.”

Don LeMay, Northwest Ore Division manager for LTV Steel Co., said the canyon-size Donora Pit his company leases from U.S. Steel Co. is expected to be scraped clean of the precious mineral in another three or four years.

“Yes, we’re going to miss it,” LeMay said. “We cherish that type of material.”

Compared to taconite, natural iron ore is steelmakers’ gravy. For every 100 tons scooped from the 1,200-acre Donora Pit and sifted through a washing plant, about 80 tons are left for the blast furnace. By the time 100 tons of taconite are processed into ore-grade pellets, only 33 tons are left for making steel.

In addition, a ton of natural ore costs less to produce and burns more efficiently in blast furnaces because it is first shaped into a porous rock-like material by fusing it with another compound.

LeMay said the Donora supply of natural ore has given LTV a small competitive edge over other U.S. steelmakers, who rely on the abundance of high-grade natural ore in Brazil and other countries in addition to domestic and Canadian taconite. LTV ships its natural ore from Duluth to Indiana Harbor, Ind., where it is made into steel.

“Our operation has been going out of business ever since I joined it,” said Mike Sterk, manager of engineering.

“We consider ourselves a vanishing breed,” said Gene Garner, mine engineer.

When LTV filled its first train car of natural ore at the mine in 1983, the workers followed tradition and planted an evergreen tree in it.

3 Million Tons

That was when they were still digging in the Stephens Pit started by U.S. Steel. When that pit was nearly exhausted in the fall of 1983, digging commenced at the adjacent Donora Pit. More than 3 million tons of the resource have been removed from the site since then and another 3 million tons are left, Sterk said. By the time the shovels are scraping quartzite at the bottom, they will be 350 feet below the upper rim.

Co-workers Paul Kaska, 52, of Gilbert and Matt Turner, 49, of Eveleth say the end sometime in 1992 will be bittersweet. They will miss the fraternity developed during long years of natural ore mining all over the range but enjoy the leisure of retirement. Kaska said all but about a half dozen of the 70 hourly wage earners at Donora will be eligible for a pension when the end arrives. The others may find work in LTV’s taconite operations on the Iron Range, they said.

“No more eating out of lunch buckets,” Kaska said. “And I remember once that I had to work when it was 52 below (zero).”

Turner said the wage and pension cuts accepted by union workers during the mining depression earlier in the decade will be among his biggest memories, and he said many men are looking forward to the day when they don’t have to drive to work. As natural ore operations moved east along the Mesabi, most miners stayed in their hometowns and were left with drives of up to 90 miles away to Aurora.