WASHINGTON, D.C. — The U.S. Senate voted 50-49 on Thursday to overturn a 20-year moratorium on mining near Minnesota's Boundary Waters canoe area wilderness. The measure, already approved by the House of Representatives, now heads to President Donald Trump.

The Biden administration imposed the moratorium in 2023, barring mining across 225,000 acres (91,000 hectares) in the Superior National Forest. Republican Senators Susan Collins of Maine and Thom Tillis of North Carolina joined Democrats in voting against the measure. Senator Josh Hawley of Missouri did not vote on the resolution.

The vote benefits Twin Metals Minnesota, a subsidiary of Chilean mining company Antofagasta PLC, which is seeking to build a copper and nickel mine a few miles from the Boundary Waters. The project must still secure federal leases and state permits before proceeding. The Boundary Waters canoe area wilderness is an interconnected complex of lakes, rivers and forests and is among the most visited wild areas in the U.S.

Kathy Graul, a spokesperson for Twin Metals Minnesota, said the vote was a critical moment for the nation's ability to strengthen mineral supply chains. She said the company is one of several focused on responsibly developing minerals in the Duluth Complex, which she described as the world's largest known undeveloped deposit of copper, nickel, cobalt, and platinum-group metals. Graul said any proposed mining project in the region must undergo a years-long, multi-agency regulatory review before earning construction permits, and that lifting the moratorium restores that process and requires projects to meet Minnesota's environmental standards before moving forward.

Democratic Senator Tina Smith of Minnesota argued that repealing the ban would expose the Boundary Waters to the toxic and destructive impacts of sulfide or copper mining. She said the measure was the opposite of an America First approach, noting that the mining company is foreign-owned, will use Chinese state-owned smelters, and will sell the extracted metals on the open market.

"Do not lose hope. This fight is not over. We should all be so proud of the coalition we built to fight this," Smith said.

Ingrid Lyons, executive director of Save the Boundary Waters, said the vote was a dark day for the wilderness area and a stark warning for public lands nationwide. She said Minnesotans and the American public have clearly stated that the Boundary Waters needs protection, and that the people who claim to represent them ignored and silenced them. Lyons said the group will continue fighting.