Twin Metals Minnesota has formally submitted its plans for a mine project near the Boundary Waters Canoe Area Wilderness to state and federal agencies.
The company said the submission "marks the culmination of of more than a decade of engineering, hydrogeological, environmental and engagement work" on the proposal.
The Mine Plan of Operations was submitted to the U.S. Bureau of Land Management and the Minnesota DNR, though it is already facing objections from environmental groups including the Campaign to Save the Boundary Waters.
Earlier this year, the Trump Administration renewed a 10-year lease for mineral exploration for the land just outside the Boundary Waters, after it had previously been mothballed under President Barack Obama.
Twin Metals Minnesota, owned by Chilean mining giant Antogafasta, wants to mine minerals including copper and nickel in a large area of Superior National Forest land nine miles southeast of Ely.
"I truly believe the Twin Metals project will be a model for modern, sustainable and environmentally responsible underground mining,” said Kelly Osborne, Twin Metals CEO.
"We’ve pulled together the best professionals in the industry who’ve put in thousands of hours to make this an extraordinary Project, and I’m proud to lead this team.'
The submission of the proposals will spark the start of an environmental review process that is expected to take years, and involve a mixture of federal, state and tribal governments.
It would become Minnesota's first underground mining operation since the closure of the Pioneer Mine in Ely in 1967, but environmental and tribal groups have expressed stern opposition.
The Campaign to Save the Boundary Waters organization has accused the Trump Administration of rigging the federal process to fast-track the project by halting an Obama-era comprehensive federal study of mining in Superior National Forest before it could be completed, and withholding the data accumulated to that point.
On Tuesday, the Office of Gov. Tim Walz said that the Boundary Waters is "deeply – and personally – important" to him, and that no mining project should move forward "unless it passes a strict environmental review process that includes meaningful opportunities for public comment."
But Save the Boundary Waters CEO Tom Landwehr, who is a former DNR Commissioner, said during a Tuesday press conference that current state standards are not sufficient to protect the Boundary Waters in the event the project goes ahead.
He says that state environmental reviews don't consider the effects on homeowners and outdoor recreation businesses, and the tens of thousands who go to hunt and fish in the Boundary Waters each year.
He said it would be a "miracle" if the mining operation doesn't leak heavy metals or sulfuric acid into the watershed, saying the project poses an "unacceptable risk" to the wilderness.
The campaign has also cited a study from Harvard University last year, which said protecting the Boundary Waters would be more economically beneficial in the long term than allowing for mining.
Twin Metals has said the project will create 765 jobs over its 25-year life, and that the mine would be access by two 20'x20' ventilated tunnels around 1.25 miles long.
The project has support from mining interests in the Iron Range, as well as politicians including Republican 8th District Rep. Pete Stauber, and DFL Senate Minority Leader Tom Bakk, who has vowed to push Gov. Walz to approve the project despite opposition from many of his colleagues.
"We need the jobs and metals this project will provide, so I look forward to seeing our hardworking miners meet or exceed every local, state, and federal environmental regulation," Rep. Stauber said on Wednesday.