Copper-nickel mining could move south of the Iron Range

Drill cores stored in 'v rails'
Drill cores are stored in "v rails" at Kennecott Exploration's core shed in Tamarack.
Dan Kraker / MPR News

If Minnesota enjoys another mining boom, it may not be limited to the Iron Range.

Although towns like Babbitt and Hoyt Lakes are on the leading edge of the current wave of copper-nickel mine development, mining companies also are exploring much farther south, in an area without a rich mining history.

Such explorations have brought workers about an hour west of Duluth to a swampland just outside of Tamarack, population 94.

As workers fired up a drill rig on Aug. 21, they extracted a 10-foot section of drill core — a tube of rock about three inches thick extracted from 600 feet below the marsh.

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"There's some nice mineralization for us," said David Simpson, exploration manager for Kennecott Exploration, an arm of global mining giant Rio Tinto. "And that's exactly what we were hoping to find in this hole. So it's quite encouraging, actually, I'm excited to see that."

Simpson, a geologist, has been exploring for nickel and copper in the swamps of Aitkin County for the past 12 years.

Mats enable heavy equipment access to drill sites.
"Swamp" or "wetland mats" are used to enable heavy trucks and equipment to access drilling sites located in tamarack swamps in northeastern Minnesota.
Dan Kraker / MPR News

But at one point, the company was close to walking away. That changed in February, 2008, with a big find.

"We hit some very good grades of nickel and copper, and that gave the program some new life," said Matt Jeschke, regional communities manager for Kennecott.

Since then, the company has methodically drilled more than 200 holes, trying to piece together a puzzle buried several hundred feet underground. But it's tedious and expensive work, at a cost of about $100,000 per hole.

More often than not, Simpson said, they'll miss.

"These deposits flow like rivers, and through channels, through the ground, you can imagine in three dimensions something like that, so it's really hard to model them, to target them from the surface," he said. "Drilling these types of deposits, probably more than any other kind of mineral deposits in the world, is a challenge because they are so irregular."

But the company has made some tantalizing discoveries. Some holes have penetrated "massive sulfide" deposits — like the chunks of ore drilled in 2012 that glitter with bronze and gold-colored specks.

Removing a drill core
Lenny Rager of Cascade Drilling prepares to remove a 10-foot section of rock from inside the drill section.
Dan Kraker / MPR News

One box in the company's core shed in Tamarack holds rock that contains metal worth up to $800 a ton — far more than the $30 or less per ton that lower-grade rock will bring.

Kennecott has found some grades of up to 5 percent nickel, and between 5 and 7 percent copper. That's far richer than the deposits PolyMet and other companies want to mine in what's known as the Duluth Complex, farther north in the Superior National Forest — although those deposits are much larger. The metal content of the ore PolyMet seeks to mine, for example, is only about .75 percent combined for copper, nickel and precious metals.

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The deposit Kennecott is exploring near Tamarack also is much more concentrated, with a much smaller volume of ore compared to deposits that could be excavated by PolyMet or Twin Metals, another mine proposed on the Duluth Complex, near Ely.

That means that means any potential mine near Tamarack would cover less surface area, Jeschke said.

He compares it to a project called the Eagle Mine that Kennecott developed in Michigan's Upper Peninsula. Scheduled to begin mining later this year, the operation will process about 4,000 tons of ore per day. One eighth the size of Polymet, it will operate for eight years, compared to PolyMet's 20-year mining plan.

Kennecott is also exploring primarily for nickel near Tamarack. That also sets the company apart from PolyMet, which primarily is targeting copper.

Another difference is how the company was received by local communities, at least at first.

Unlike PolyMet, which has largely been welcomed on the Iron Range with its long connection to mining, Kennecott got off to a rocky start in Tamarack.

Kathy Haugse and her husband own Sam's Grocery.
Kathy Haugse and her husband Sam have owned Sam's Grocery in downtown Tamarack for 36 years.
Dan Kraker / MPR News

The company's decision to send low-flying airplanes over town to conduct electromagnetic surveys didn't help, said Kathy Haugse, owner of Sam's Grocery in Tamarack.

"People would come in and say, 'There's planes flying over, they're bombing things, there are strange cars driving all over, there are strange people all over,'" she recalled.

For a while, the rumor mill ran rampant, Haugse said.

"You get people from all over the world showing up with different accents, a different vocabulary," she said, "and you're wondering, what are they doing in Tamarack? People really wanted to know. And it's our right to know. Cause this is our home."

But Haugse said the company slowly earned her trust. She hosted informal gatherings and potlucks around a table on the second floor above her store, where locals could ask questions at what became "the most popular table in Tamarack."

Since Kennecott opened a downtown office in 2007, company officials have been more responsive to questions and concerns, Haugse said.

A mine would be a huge shot in the arm for the Tamarack area, which struggled ever since dairy farms began folding in the 1960s and '70s, Mayor Bob Johnson said.

"If it should ever come here it would be a tremendous boost economically for everybody," Johnson said. "Our school district would definitely benefit."

Sam's Grocery in Tamarack
Sam's Grocery in downtown Tamarack is a community hub where locals come to learn about Kennecott's ongoing exploration for nickel, copper and precious metals nearby.
Dan Kraker / MPR News

Haugse said the mining activity so far has been both good and bad for her general store. Some people, she said, "won't shop there because I have an association with Kennecott."

Kennecott also has purchased hundreds of acres of land formerly used for hunting around town. Haugse said that will hurt her deer and bear processing business, the biggest chunk of her income.

But on the positive side, she said, the company patronizes her business and others in town as much as possible.

As it has elsewhere in Minnesota, the prospect of copper-nickel mining has also raised fears of potential water pollution. The swampland near Tamarack drains into Big Sandy Lake, a major reservoir north of McGregor that feeds the Mississippi River.

Bruce Johnson, president of the Big Sandy Lake Association, worries about mine runoff.

"We want to know what they're going to do to keep the runoff from going in the lake, to protect the chemical balance in our lake," Johnson said.

Kennecott officials say they can't answer those specific questions until they better understand the deposit.

Earlier this summer Kennecott reached a deal with a smaller company called Talon Metals that should help bring clarity to the project. Talon is investing roughly $30 million over the next three years to ramp up exploration.

By then, Kennecott officials should know whether the company aims to push the project forward. But any potential mining is still likely at least a decade away, if it happens at all.

"What we know for now is we finally got the ability to really go after this," said Jeschke, the company's regional communities manager. "To see if we can get to that next stage."