Outdoor enthusiasts travel by canoe to some of the hundreds of freshwater lakes that make up the Boundary Waters in Minnesota’s northern woods.
Andrew Lichtenstein Corbis News | Getty Images
The Senate on Thursday overturned a moratorium on mining in Minnesota’s Superior National Forest. This was a boon for the Chilean mining company’s subsidiaries and a painful loss for environmentalists trying to protect the Boundary Waters Canoe Area’s virgin forest.
The chamber voted 50-49 to overturn protections set in place by President Joe Biden for 20 years through 2023. This clears the way for a long-stalled mining project proposed by Twin Metals of Minnesota to access vast reserves of copper and other minerals in the Superior National Forest near the Boundary Waters. This is the latest step in a long battle over mining in the area. The project has been oscillated between Democratic and Republican administrations for years, with environmental groups warning it could pollute the nation’s most visited natural areas.
The mine was sought by Twin Metals, a subsidiary of a Chilean mining conglomerate. antofagastaaims to access the copper, nickel, cobalt and platinum buried deep beneath the surface of senior national forests. The site itself is outside the Boundary Waters, and while the company denies concerns of contamination, opponents say it is inevitable that hazardous chemicals will leak into the Boundary Waters.
“Twin Metals Minnesota is one of several companies committed to the mineral development of the Duluth Complex, the world’s largest known undeveloped copper, nickel, cobalt and platinum group metals deposit,” Twin Metals spokeswoman Kathy Graul said in a statement to CNBC. “Mineral extraction enacted in 2023 has resulted in significant portions of these resources being locked up and negatively impacting communities across the Iron Range.”
“The Twin Metals team looks forward to robust discussions and engagement with the community throughout the future regulatory process,” Graul added.
Republicans who pushed for the resolution praised the outcome. The changes were made under the Congressional Review Act, which allows Congress to overturn new executive rulemakings with a simple majority vote. It passed the House in January.
“Today, a landslide victory for America and Minnesota’s 8th District is secured,” Rep. Pete Stover (R-Minnesota) said in a post on X. “The Senate just passed my bill to repeal Biden’s ban on illegal mining in the Superior National Forest. Now it’s on its way to the President’s desk!”
The vote came over the objections of two Democrats and two Republicans, Sen. Thom Tillis of North Carolina and Sen. Susan Collins of Maine. Both senators warned of irreparable damage to the border waters and irregular use of the Congressional Review Act, which could hit back at the Republican majority if Democrats control the Senate.
The Boundary Waters was established as a federal conservation area by law in 1978. Nearly 2,000 lakes across 1.1 million acres in northeastern Minnesota, which borders Canada, are largely closed to motorized boats and other vehicles.
A lake located within the Boundary Waters Canoe Area Nature Preserve in Ely, Minnesota. (Photo by Salwan Georges/The Washington Post via Getty Images)
Salwan Georges | Washington Post | Getty Images
Sen. Martin Heinrich (D.M.), Ranking Member of the Senate Energy and Natural Resources Committee, called the vote a “dark day” and a “stain” on the Senate.
“As a natural resource manager and someone who has had to negotiate with copper companies in my state, I can tell you this type of copper mining has never been done without contaminating the water. Never, ever,” he said in a floor speech before the vote. “So we’re guaranteeing that we’re going to pollute the boundary waters.”
The resolution passed over the objections of Minnesota’s Democratic senators Amy Klobuchar and Tina Smith.
“We can support mining, but that doesn’t mean we support every mine everywhere,” Smith said. “Regardless of the outcome of this afternoon’s vote, we will never stop fighting and we will never stop working to protect our border waters.”
Actor Nick Offerman leads a debate at the U.S. Capitol on Wednesday, April 15, 2026.
Bill Clark | CQ-Roll Call Inc. | Getty Images
Overturning the mine moratorium also involved considerable outside pressure, including from figures like actor Nick Offerman.
“Enjoying the Minnesotan/Canadian wilderness in a canoe or other watercraft is one of the greatest pastimes available in our country, and one that I have enjoyed all my life,” Offerman said in a post on X on Wednesday. “We must protect these public lands from greedy capitalists who threaten to turn them into toxic wastelands.”
Ingrid Lyons, executive director of the advocacy group Save the Boundary Waters, said the vote goes against the will of Minnesotans.
“Today is a dark day for America’s most beloved nature preserve, the Boundary Waters Canoe Area Wilderness, and a stark warning is being called for on public lands across the country,” she said in a statement. “Minnesota and the American people have been saying loud and clear that this iconic site must be protected. Today, they have been ignored, and worse, silenced, by the very people who claim to represent Minnesotans and the American people.”
Public lands became a flashpoint in this Congress. Some Republican lawmakers pushed for the sale of large portions of federal property as part of a tax and spending bill last year, but the move was backed down after resistance from outdoor and hunting groups and staunch opposition from members of the Montana delegation.
The bill now heads to President Donald Trump’s desk. He is expected to sign it.
