Defending the Boundary Waters from sulfide mine pollution

The Boundary Waters is one of the most iconic wilderness areas in the world and the most visited wilderness in the U.S., and it’s at risk of contamination from extractive industries. MCEA uses our expertise and legal resources to protect it, as well as all of Minnesota’s irreplaceable wild places. 

Twin Metals, an international mining conglomerate owned by Chilean mining giant Antofagasta, wants to build and operate one of the most toxic industries in the world - sulfide mining - just south of Ely, Minnesota, where the inevitable pollution caused by it would flow directly into the Boundary Waters. This watery wilderness is fragile, and any water pollution could devastate the area. 

The proposal has a long history with many ups and downs. In 1966, International Nickel Company (INCO) acquired two federal mineral leases, one near Birch Lake and the other along the Spruce Road, just ¼ mile from the wilderness boundary. In the 1970’s, concern over pollution led to a four-year moratorium on copper mining, and a state study into copper-nickel mining pollution risks. Low prices for copper and other metals cooled interest in the deposit, and it lay fallow for years. But these leases remained, and eventually sprang to life as Twin Metals Minnesota. 

In 2010, Canadian junior mining company Duluth Metals announced a joint venture with Chilean mining giant Antofagasta. Antofagasta later purchased Duluth Metals in its entirety, assuming 100% ownership.

In 2016, it looked like this proposal was dead, as the U.S. Forest Service and Bureau of Land Management refused to extend the federal mineral leases. However, the Trump administration reversed this decision and gave the leases back to Antofagasta. As Antofagasta pushed for state and federal regulators to move forward with environmental review and permitting, environmental groups including Friends of the Boundary Waters Wilderness, Campaign to Save the Boundary Waters, and Northeastern Minnesotans for Wilderness brought a variety of legal challenges to the reinstatement of the leases, environmental review, and state mining rules. 

After appearing to hit a dead end several times, the Minnesota Department of Natural Resources (DNR) began an environmental review of the proposal in 2020, and the process slowly moved forward.  

Then, in 2022, the Biden administration announced that federal mineral leases for the Twin Metals project had been improperly renewed, and it canceled those leases–meaning that Twin Metals no longer had the right to build its mine as planned. The following year, the Biden administration announced a 20-year moratorium on mining in 225,000 acres of the Superior National Forest that would protect the Boundary Waters from mining pollution. 

The moratorium was a massive victory that brought immense relief for Minnesotans and people around the world determined to keep the Boundary Waters protected. 

But it was undone in 2026 when President Donald Trump signed a Congressional Review Act resolution lifting the 20-year federal ban on copper-nickel mining across roughly 350 square miles of the Superior National Forest watershed. The legislative action paves the way for the Twin Metals project, owned by the Chilean mining firm Antofagasta, to again apply for permits near the Boundary Waters Canoe Area Wilderness.

MCEA and other environmental organizations across the state and country remain determined to use our collective expertise, legal resources, and Minnesota’s environmental laws to keep this iconic wilderness protected.