The Boundary Waters Canoe Area Wilderness (BWCAW) in northeastern Minnesota is one of the last truly pristine freshwater wilderness areas in the United States. This million-acre sanctuary of interconnected lakes and forests is more than a vacation destination—it’s a cultural landmark, a biodiversity stronghold, and a critical water source. But the looming threat of copper-nickel mining near its watershed could change that forever.

Photo: Wikimedia Commons / United States Forest Service, License: Public Domain

The Boundary Waters is one of the most protected wilderness areas in the U.S.

Copper Mining and the Risk to Water

Sulfide-ore copper mining carries a unique risk to the waters that feed into the Boundary Waters. Unlike iron mining, which has been a staple of Minnesota’s economy for over a century, copper-nickel mining involves extracting metals from rock that produces sulfuric acid when exposed to air and water. This acid can leach toxic metals into waterways, with impacts that scientists warn may be irreversible.

The mining would take place in the Rainy River Watershed, upstream of the BWCAW and Voyageurs National Park. According to a U.S. Forest Service study released during the Biden administration, hard-rock mining in this region could pose a significant environmental threat to the entire watershed, which includes the 225,000 acres targeted for protection by recent legislation from Sen. Tina Smith, reports the Twin Cities Pioneer Press.

Photo: Wikimedia Commons / Geoffrie, License: Public Domain

Copper-nickel sulfide mining has never operated without polluting nearby water.

Efforts to Enact a Permanent Ban

In response, Smith introduced a bill in the Senate that would ban copper-nickel and other sulfide mining in this sensitive area of the Superior National Forest. The proposal builds on a 20-year moratorium imposed by the Biden administration in 2023 and aims to enshrine those protections into federal law.

Supporters of the legislation point to the vulnerability of the watershed and the cultural and ecological significance of the BWCAW. The area is home to endangered species such as lynx and sturgeon and is a vital recreational economy driver for surrounding communities, The Wilderness Society reports.

Yet, despite broad public support for preserving the BWCAW, the legislation faces a difficult road ahead. Both chambers of Congress are currently controlled by Republicans, and opponents have positioned the bill as anti-labor and anti-development. As Star Tribune reports, Rep. Pete Stauber has introduced a competing bill to undo the mining moratorium and restore mineral leases to Twin Metals, the Chilean-owned company behind the proposed mine near Ely, Minnesota.

Photo: Wikimedia Commons / dan carlson, License: Public Domain

Twin Metals plans to mine just miles from the Boundary Waters’ edge.

“Prove It First” and Other Safeguards

Separate but complementary efforts in Minnesota’s state legislature have also taken aim at stopping mining projects unless companies can prove their safety. The “Prove It First” bill would block new copper-nickel mining unless a company can point to a similar operation that has run for ten years without polluting—and remained clean for ten years after closure.

Other measures include the “Bad Actor” bill, which bars companies with histories of environmental violations from mining in Minnesota, and the “Taxpayer Protection Act,” which requires mining companies to cover cleanup costs in advance rather than rely on taxpayers to pay for disaster response. These bills are critical given the industry's track record; mining companies across the U.S. have left behind hundreds of toxic sites now classified as Superfund locations, MinnPost reports.

Photo: Wikimedia Commons / U.S. Department of the Interior, License: Public Domain

Sen. Tina Smith introduced legislation to make a mining ban permanent.

Local Voices and a National Debate

The threat to the Boundary Waters has mobilized a wide coalition—from tribal communities and outdoor enthusiasts to business owners dependent on clean water. According to The Wilderness Society, the region is part of the Anishinaabe homeland, and mining in these lands presents not only an environmental risk but a cultural and treaty rights concern.

At a recent public hearing, testimonies ranged from industry veterans to teenagers like Clair Peterson, who called on lawmakers to defend the waters instead of letting them become a toxic liability.

“I’d rather spend the rest of my life planning trips to the Boundary Waters than trying to clean it of sulfide sludge,” she told MinnPost.

Photo: Wikimedia Commons / U.S. Fish and Wildlife Service - Midwest Region, License: Public Domain

Mining risks wild rice beds, fisheries, and fragile ecosystems.

Not All Mining, Just Not Here

Sen. Smith has made it clear that her bill is not a blanket rejection of mining. Taconite and iron mining, already prevalent in Minnesota, are exempt from the proposed ban. The focus is narrowly on sulfide mining in an ecologically sensitive watershed that drains into one of the most visited wilderness areas in the country.

“This isn’t about opposing all mining,” she told MPR News. “It’s about protecting this one-of-a-kind place from a type of mining that could destroy it.”

As the federal government signals a push for increased domestic mineral production, the debate over the Boundary Waters may be a bellwether for how the country balances the need for critical minerals with the duty to safeguard its last wild places.

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