PUBLIC LANDS WATCH

Boundary Waters Canoe Area Wilderness (Superior National Forest watershed)

Superior National Forest, northeastern Minnesota, near Ely · Wilderness Area (BWCAW); threat concerns adjacent Superior National Forest mineral leases · managed by U.S. Forest Service / Bureau of Land Management

Status: Reversed — 20-year mining ban overturned; leases advancing Threat: Sulfide-ore copper-nickel mining — mineral withdrawal reversal
Coordinates
47.9, -91.5
Page last verified
2026-08-12
Site maintainer of record
Alicen M.
File
/boundary-waters

01 — Historical & Cultural Record

The Boundary Waters Canoe Area Wilderness spans roughly 1.1 million acres and is the most visited federally designated wilderness area in the United States, drawing nearly 150,000 visitors in 2024. Twin Metals Minnesota, a subsidiary of the Chilean mining conglomerate Antofagasta, has sought to build a copper-nickel sulfide mine near Ely and Babbitt, upstream from the BWCAW, using mineral leases first issued in 1966 (MNES-01352 and MNES-01353). In 2016, the Obama administration declined to renew those leases. In 2022, after a multi-year environmental review, the Biden administration formally canceled the leases, citing risk of acid mine drainage into the Boundary Waters watershed. In January 2023, a 20-year mineral withdrawal (mining ban) was ordered across approximately 225,000 acres of the Superior National Forest to protect the watershed from future hardrock mining.

02 — Current Threat

In 2018, during the first Trump administration, the leases were reinstated in a move later found unlawful. In 2026, the second Trump administration moved to revive the project: DOI Deputy Secretary Katherine MacGregor signed a memo reversing a 2022 legal opinion that had invalidated the leases, and on June 3, 2026 the House Appropriations Committee advanced FY27 Interior appropriations language directing federal agencies to reinstate the two Twin Metals leases. On April 16, 2026, the Senate passed a resolution overturning the 20-year mineral withdrawal across the 225,000-acre area (50-49 vote); the House had already passed it, and President Trump signed it on April 27, 2026. This legislative approach — directing agencies to grant leases the company does not currently hold, rather than restoring prior rights — was noted as an unusual mechanism by opponents. Twin Metals still needs its mineral leases formally approved and must pass federal and state permitting processes before mining could begin.

03 — Documented Impact: Environmental

Geology & Ore Body: Northeastern Minnesota sits atop the Duluth Complex, a major deposit of copper, nickel, cobalt, and other precious metals. Unlike most historic Minnesota iron mining, these metals are bound in sulfide-bearing minerals.

Water & Contamination: The central documented risk is acid mine drainage: when sulfide minerals are exposed to air and water during mining, they can generate sulfuric acid and release other pollutants. The Biden administration's 2022 lease cancellation and 2023 withdrawal were explicitly based on a multi-year environmental review finding this risk unacceptable for the BWCAW watershed. The Boundary Waters is a uniquely interconnected wilderness of lakes, rivers, streams, and wetlands with limited natural buffering capacity against pollutants, making it especially vulnerable to any sulfate or heavy-metal loading. Sulfate increases in water are documented to damage wild rice — a culturally and ecologically significant plant in the region — and to contribute to the creation of methylmercury, the form of mercury that bioaccumulates in fish tissue and moves up the food chain, including into fish consumed by humans.

Habitat: A dedicated wildlife/endangered-species inventory specific to the mine footprint is not yet documented in current sourcing.

Long-Term Effects: Once initiated, acid mine drainage is a process that can continue for decades to centuries after a mine closes, since exposed sulfide rock continues reacting with air and water indefinitely absent active, continuing remediation — a standard concern cited broadly in sulfide-mining risk literature and specifically invoked in the 2022/2023 federal review of this project. The BWCAW's status as an interconnected watershed means contamination introduced at the mine site is not contained to a single location but can migrate through the connected lake system over time.

03 — Documented Impact: Cultural & Archaeological

Not yet documented — awaiting a specific cited cultural/indigenous-resource assessment for this site.

03 — Documented Impact: Economic & Fiscal

Statewide, outdoor recreation contributes an estimated $13.9 billion annually to Minnesota's economy, compared with $1.2 billion from extractive industries including mining, according to Save the Boundary Waters' published analysis. The only peer-reviewed, published economic study of the proposed Twin Metals project reportedly found the region would see more jobs and income with no copper mining in the headwaters than with the mine operating. A federal agency announcement previously cited concerns about impacts to a nearly $45 million regional recreation economy specifically tied to the watershed. Twin Metals has stated much of its mining workforce would come from outside Minnesota and outside the U.S., citing an insufficient local technical talent base — a claim relevant to promised in-state job creation figures.

03 — Documented Impact: Legal Status

Earthjustice, representing The Wilderness Society, Izaak Walton League of America, and the Center for Biological Diversity, previously sued over the first Trump administration's 2018 lease reinstatement and successfully defended the Biden administration's 2022 cancellation. Following the April 2026 congressional resolution and the DOI legal-opinion reversal, Earthjustice has stated the fight is continuing; Twin Metals still requires lease approval and full federal/state permitting, a process expected to take years and likely draw further litigation.

03 — Documented Impact: Human Health

Not yet documented — no dedicated human-health impact study specific to this project (e.g., for downstream communities or mine workers) was identified in current sourcing, beyond the general mercury-bioaccumulation-in-fish pathway noted in the environmental section, which has documented human health relevance for subsistence and recreational anglers.

03 — Tribal / Public Consultation Status

Not yet documented — a tribal consultation record specific to this project was not identified in current sourcing.

04 — Named Companies & Responsible Parties

05 — Recorded Opposition & Support

06 — Timeline of Developments

07 — Sources

Primary

Secondary

Corrections Log

None on record as of 2026-08-12 (page last substantially expanded).

Take Action

No published federal comment deadline on record as of last verification; legislative and regulatory actions are ongoing.

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