Just days after President Donald Trump visited Minnesota, underscoring his support for copper-nickel mining near the Boundary Waters Canoe Area Wilderness, local opponents have ramped up their court battle to block mineral leases approved by his administration.

A coalition of local businesses, environmental advocates and outdoor recreation groups on Wednesday filed a motion for summary judgment in their lawsuit against the U.S. Department of Interior and Twin Metals Minnesota. They're asking a federal judge to rule without a trial that the Trump administration last year wrongly reinstated two mineral leases for Twin Metals Minnesota to build a copper mine on Birch Lake near Ely.

It's the latest shot in the state's prolonged battle over copper-nickel mining in northeastern Minnesota, a prospect that has raised hopes for the region's economy while triggering alarms about grave environmental risks.

The Department of the Interior has until mid-May to respond to the motion. A spokeswoman for Twin Metals said the company doesn't comment on ongoing litigation.

The Twin Metals proposal for an underground mine is one of two fiercely contested copper mines proposed near the Boundary Waters wilderness. It appeared dead three years ago, after state and federal leases were denied by then-Gov. Mark Dayton and President Barack Obama.

Trump's Interior Department, however, quickly reversed course last year, renewing expired mineral leases for Twin Metals and canceling an environmental review that was to be conducted by the U.S. Forest Service.

Lawyers for the Minnesota opponents argue that the flip-flop by U.S. Depart of the Interior and its Bureau of Land Management is illegal.

"There is no statute or regulation that gives the Bureau authority to reinstate expired mineral leases," they said in the filing.

Twin Metals Minnesota, a subsidiary of the Chilean mining giant Antofagasta, has said it has invested more than $400 million on exploration and other work to develop the mine, and that it will adhere to strict environmental regulations.

After the Interior Department responds to the motion, which was filed in U.S. District Court in the District of Columbia, oral arguments are expected in the fall. A decision could come by the end of the year.

Plaintiffs in the lawsuit include more than a dozen companies and organizations, including Voyageur Outward Bound School, Friends of the Boundary Waters, River Point Resort & Outfitting Co. and the Campaign to Save the Boundary Waters.

Friends spokesman Pete Marshall said that if they lose, they will appeal and ask for a stay of the lease renewal while the court challenge plays out.

"The current decision that reversed that decision is based on pretty shaky, pretty tortured reasoning," Marshall said.

Officials at the U.S. Department of Justice could not immediately be reached for comment.

The court challenge is part of a rapidly widening battle over the Trump administration's support for Twin Metals. U.S. Rep. Betty McCollum, a Democrat who runs the House committee in charge of the Interior Department's budget, has grilled agency officials in committee hearings and ordered them to produce documents related to the lease decisions. Tom Landwehr, who served as Minnesota's commissioner of natural resources under Dayton, has since taken the helm of the Campaign to Save the Boundary Waters, which is focused on stopping the Twin Metals project.

Quick decisions fail

The Twin Metals lease decision is one of many issued by the Trump administration in a sweeping effort to overturn Obama-era policies on the environment, consumer safety, immigration and other topics. But many have wound up snarled in the courts.

A recent study by researchers at the New York University School of Law found that the Trump administration has lost roughly 95% of the cases when it was challenged under the decades-old federal Administrative Procedures Act. Previous presidents typically won roughly 70% of such cases, according to the law school's Institute for Policy Integrity.

"It's kind of a train wreck," said Bethany Davis Noll, the Institute's litigation director.

Davis Noll said judges have repeatedly faulted the legal and factual grounds of decisions issued rapidly by officials in the Trump administration.

The judge currently assigned to the Twin Metals lease lawsuit, U.S. District Judge Trevor McFadden, is a Trump appointee. However, Davis Noll said she does not think that would make him any less likely to support the Administrative Procedure Act.

"I don't see the Trump appointed judges wanting to tear that down," Davis Noll said.

While Minnesota has a rich history in taconite mining, hard rock mining carries greater environmental risks because copper is extracted from sulfur-bearing ore that, when exposed to oxygen or water, generates toxic sulfuric acid that can pollute nearby waters — a toxic discharge often called acid mine drainage.

The project furthest along is an open-pit mine proposed by Poly Met Mining Inc., a subsidiary of Poly Met Mining Corp. in Canada, which is owned largely by the Swiss-based conglomerate Glencore.

PolyMet is developing a copper nickel mine and processing plant at an existing taconite site south of Babbitt. It has received all of its required state permits, although it still faces at least seven legal challenges.

The Twin Metals project is in the early stages of permitting. The company is expected to submit its mining plan of operation in the coming months.

Jennifer Bjorhus • 612-673-4683