Senate lifts mining ban near Boundary Waters, boosting Twin Metals project

The narrow Senate vote to lift a 20-year mining withdrawal near the Boundary Waters cleared a major hurdle for Twin Metals Minnesota, but it did not hand the company a mine. It reopened 225,504 acres of federal land in Cook, Lake and St. Louis counties to mineral and geothermal leasing, setting up a fresh round of permitting, environmental review and legal combat over the future of the Rainy River watershed.

By a 50-49 margin on Thursday, April 16, the U.S. Senate approved H.J.Res. 140, overturning Public Land Order No. 7917, the 2023 federal withdrawal that had kept those lands off-limits for 20 years. The affected area sits in the watershed that drains toward the Boundary Waters Canoe Area Wilderness, the wilderness area federal officials have described as the most heavily visited in the United States. For Twin Metals, a subsidiary of Chilean mining company Antofagasta, the vote removes a federal obstacle that had stood in the way of its copper-nickel project near Ely.

Even with the Senate action, Twin Metals still has to reapply for mining rights and move through state and federal permitting before any underground mine could advance. That means the company remains years away from production, if it gets there at all. The latest vote changes the political terrain more than the physical one: it opens the door, but it does not approve the mine.

The fight has drawn a hard line through northeastern Minnesota. Supporters on the Iron Range cast the vote as a jobs-and-investment victory for a region that has long depended on mining work. Opponents say the stakes are permanent, not temporary, because sulfide-ore copper mining near the Boundary Waters could threaten water quality in the Rainy River watershed and undercut an economy built around wilderness travel, outfitters and tourism.

Minnesota Sen. Tina Smith tried to slow the vote with an hourslong floor protest, using the Senate debate to argue that rolling back the withdrawal would put the Boundary Waters at risk. Conservation groups, including Save the Boundary Waters, Earthjustice and American Rivers, have warned for years that the 2023 withdrawal was necessary to protect the watershed, the Boundary Waters Canoe Area Wilderness Mining Protection Area and the 1854 Ceded Territory of the Lake Superior Chippewa.

The resolution now awaits final action by President Donald Trump. If he signs it, the political battle will shift back to the agencies and the courts, where Twin Metals, environmental groups and tribal interests are likely to collide again over whether copper, nickel and cobalt should be extracted near one of Minnesota’s most fragile and economically important landscapes.