The Fight Over Toxic Mining Returns to Minnesota’s Boundary Waters
Now that Congress has rolled back protections from mining in its watershed, the beloved haven for paddlers and wildlife is once again at risk.
By Maddie Burakoff
Associate Editor, Audubon magazine
Published September 23, 2026
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When Jason Zabokrtsky first paddled Minnesota’s Boundary Waters in 1997, he was stunned by a vast wilderness. “It was powerful to see that there were still places like this in the world,” says Zabokrtsky, who now runs the nearby Ely Outfitting Company. The glacier-carved region’s striking geology and lush boreal forest are pocketed by 1,100-plus pristine lakes, an ecosystem so special that the federal government protected 1.1 million acres as the Boundary Waters Canoe Area Wilderness in 1978. Today some 150,000 paddlers, fishers, and campers—and a brilliant array of breeding birds—visit each year.
Yet efforts to tap mineral deposits near the wilderness, upstream in its watershed, have long imperiled the landscape. Recent state and federal actions have now revived what Ingrid Lyons, executive director of Save the Boundary Waters, describes as a “ping-ponging issue.” Though extractive industry is outlawed in the wilderness area, this spring Congress overturned a 2023 ban on mining adjacent federal land in Superior National Forest, citing demand for copper. In August, Minnesota Governor Tim Walz countered with an executive order that blocked the state from permitting mines for copper and certain other minerals within the watershed.
Central to the matter are two federal mining leases that predate some of the area’s protections.
Central to the matter are two federal mining leases in the forest that predate some of the area’s protections. Several times over the past decade, the Department of the Interior has canceled and reinstated the leases, held by Twin Metals Minnesota, a subsidiary of the Chilean company Antofagasta. Under President Biden, officials went further, establishing a 20-year mining ban on 225,000 acres after the U.S. Forest Service laid out numerous risks of mining near an “irreplaceable national treasure.”
In ending the ban, Congress also took a controversial step that could pave the way for more extraction on public lands. Legislators used the Congressional Review Act (CRA), a law that allows a majority vote to overturn some recent agency rules—and generally bars the agency from creating a similar one again. In the past, the CRA had never been used to challenge a public land order, a type of agency action that establishes plans and protections for federal lands. Now that the Interior Department has submitted one for review, “basically,” Lyons says, “there’s a Pandora’s box that’s been opened.”
The stakes in the Boundary Waters are high. Though iron mines have long operated nearby, Twin Metals’ proposed copper mine poses a greater threat, says David Chambers, a geophysicist at the Center for Science in Public Participation. The site’s valuable metals occur in sulfide-rich formations. When exposed to air and water, sulfides oxidize to produce corrosive sulfuric acid, which can leach mercury, lead, or other heavy metals from rock.
A Twin Metals spokesperson said the site’s geology and mine’s methods would ensure that acid drainage isn’t a concern. The company has filed plans to contain toxic by-products by storing waste rock and tailings underground, among other measures. Yet even with precautions, says Chambers, nearly every copper mine he’s studied has contaminated waterways: “It’s just very difficult to keep pollution restricted to the mine site.”
Any pollutants that enter the Boundary Waters can spread quickly.
Any pollutants that enter the Boundary Waters can spread quickly through its network of lakes, streams, and wetlands. They also move up the food chain from invertebrates and fish to Common Loons and Ospreys. “We’ve got this special patch of northern forest that’s really intact, really unique, and really dependent on clean water,” says Dale Gentry, director of conservation for Audubon Upper Mississippi River. Wild rice, or manoomin, is a particular concern: The aquatic plant, a food for birds and a sacred crop for Anishinaabe peoples, is sensitive to sulfates.
Though largely underground, the mine’s footprint could also disturb wildlife, says Lee Frelich, a University of Minnesota forest ecologist. Light and noise from heavy infrastructure could interfere with hunting behaviors of Canada lynx and gray wolves, while clearing trees would fragment nesting habitat for migratory and resident birds, including Boreal Chickadees and Great Gray Owls.
Walz’s recent order took several steps to impede the proposed mine, including putting a hold on the state permits that Twin Metals would need to operate. But its protections aren’t permanent. Advocates are pushing for state laws that ban sulfide-ore copper mines in the watershed for good. Meanwhile, the local mood is divided, Zabokrtsky says. Some welcome an economic boon in a region with a proud mining history. To others, the threat to a $1 billion tourism and recreation economy isn’t worth it. People visit for healthy lakes and forests, the fish and birds, the dark sky and quiet. “This is what we have that nobody else has,” he says.
This story originally ran in the Fall 2026 issue as “Below the Surface.” To receive our print magazine, become a member by making a donation today.
