ST. PAUL, Minn. (AP/WCCO) — Gov. Mark Dayton laid out his opposition to a proposed copper-nickel mine near the Boundary Waters Canoe Area in northern Minnesota on Monday.

The governor released a letter to the head of Twin Metals Minnesota saying the state will oppose any new mining agreements on state lands close to the massive outdoor recreation area.

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“As you know the BWCAW is a crown jewel in Minnesota and a national treasure,” Dayton wrote in the letter. “Its uniqueness and fragility require that we exercise special care when we evaluate significant land use changes in the area, and I am unwilling to take risks with that Minnesota environmental icon.”

Twin Metals, a joint venture between Toronto-based Duluth Metals and Chilean mining company Antofagasta PLC, wants to build the copper-nickel-precious metals mine near Ely in northeast Minnesota.

Environmentalists are fighting copper-nickel proposals in Minnesota because the metals are in minerals that contain sulfides, which can leach sulfuric acid when exposed to air and water. Mining supporters say the minerals can be mined safely and the area needs the jobs.

It wasn’t immediately clear what effect the lack of access to state lands would have on the project. But Dayton also said in his letter that he had called the director of the Bureau of Land Management, which is considering renewal of Twin Metals’ federal lease holdings, to tell him he opposes the project.

In a statement, Twin Metals said the company has received Dayton’s letter and is assessing the governor’s position

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Dayton’s letter comes a week after the Minnesota Department of Natural Resources approved the final environmental review for the Polymet proposed copper-nickel mine, paving the way for that project to pursue a long list of permits necessary to move forward. Unlike Polymet, the Twin Metals mine is in a watershed that flows into the BWCA.

In response to Dayton’s letter, Rep. Tom Hackbarth, who chairs the House Mining and Outdoor Recreation Policy committee, said the governor’s orders prevent Twin Metals from conducting even non-invasive studies that would help the project move forward.

“Minnesota has a strong history of thorough and stringent environmental review and permitting processes designed to address any concerns a potential project might have,” Hackbarth said. “The Governor is once again putting the interests of extreme environmentalists ahead of job creation in northern Minnesota.”

Environmentalists said Dayton’s letter is a big win for the BWCA and its supporters. Aaron Klemz, a spokesman for Friends of the Boundary Waters Wilderness, said the governor’s letter has both practical and symbolic effects. Klemz said the area Twin Metals is pursuing for its mine is a patchwork of state, federal and private land.

“Aside from the practical impact, the governor’s statement is a powerful piece of evidence that this mine should not go forward,” Klemz said.

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