Protecting The BWCAW
From Sulfide Mining

Sulfide mining produces toxic waste that could irreversibly damage the BWCAW’s lakes, rivers and natural resources.

This is not our grandparents’ iron mining. Sulfide mining has never been done in Minnesota. While iron mines have challenges of their own, the sulfuric acid produced with sulfide mining makes it particularly difficult to avoid polluting nearby lakes, streams and ground water.


  • Sulfide mines are being proposed on the edge of the BWCAW and exploration is occurring throughout the Quetico-Superior ecosystem.
  • Sulfide mining is the most toxic industry in the United States and has a near perfect global track record of water pollution.
  • When citizens get organized and speak up, we can protect precious places like the Boundary Waters
  • How Minnesota responds to the first sulfide mine proposal by PolyMet Mining Corp. will influence all of the other ones that may follow.


Water is the lifeblood of the BWCAW. The lakes and rivers of the Boundary Waters connect the whole region, and pollutions that starts in part of the watershed would spread. Peer-reviewed research shows that underground sulfide mining pollution would quickly move into surface water. The geology of the BWCAW can’t buffer acid mine drainage, so the risk to the BWCA is great.

Sulfide mining interest near the BWCAW isn’t limited to a single mine proposal. Hundreds of prospecting permits have been filed for minerals near the BWCA, and thousands of acres of state and federal mineral rights have been leased. One mine proposal from PolyMet Mining has already applied for state and federal permits. Chilean mining company Antofagasta is currently suing to overturn a federal government decision to end their lease on mineral rights next to the BWCAW as part of their Twin Metals mine proposal. A number of other companies, including Teck and Kennecott/Rio Tinto hold mineral rights for sulfide mining in northern Minnesota.

Local economies depend on the pristine water quality of the Boundary Waters. Economic research conducted by Conservation Economics Institute and commissioned by Friends of the Boundary Waters Wilderness found that Boundary Waters tourism had $77 million in economic impact in summer 2016, creating nearly 1,000 jobs in the communities nearest the BWCAW. A resilient, self-reliant economy in the Boundary Waters region depends on protecting the wilderness for future generations.


We activate citizens and help them raise their voice for the Boundary Waters. Our innovative organizing has connected tens of thousands of BWCAW users to public input opportunities to speak up for the Boundary Waters. We developed the online and in-person engagement strategies that resulted in record numbers of public comments on the PolyMet and Twin Metals mine proposals. We’ve turned out thousands of people to public hearings to speak for the BWCAW over the past five years.

We also know success on this issue will require effective collaboration between the people working to protect Minnesota from sulfide mining pollution. Here are the ways we’re leading and collaborating:

  • Co-founded Mining Truth, the coalition that launched sulfide mining from an unknown issue into one of the most hotly debated environmental issues in the history of Minnesota.
  • Co-lead the Campaign to Defend Lake Superior responding to the threat of the PolyMet mine proposal.
  • Members of the Campaign to Save the Boundary Waters working to oppose Antofagasta’s Twin Metals mine proposal.
  • Chaired the Minnesota Environmental Partnership Mining Cluster, a group coordinating action among all of the groups addressing sulfide mining in Minnesota.

We do the research to prove the risk of sulfide mining. We commission original research that analyzes the risk of sulfide mining and file detailed comments on sulfide mine proposals. We do more than shout, we do the homework needed to make a scientific and legal case that sulfide mining is too risky to be located next to the BWCAW. 



Raise your voice! The Interior Department is asking for public comments on whether they should stop leasing federal mineral rights in the Boundary Waters watershed to mining companies.

This would be a huge step toward permanently protecting the BWCA from sulfide mining pollution. This comment period end August 2017, so be sure to have your say today. Send your comment to the federal government.


We can’t do this work without your support. Our members help us spread the word, conduct original research, and allow us to hire the staff needed to keep pushing for protection of the Boundary Waters at the Minnesota and U.S. Capitols. Make a contribution today.

Some of the reasons for concern

  • Long-term acid and toxic metal water pollution — for instance, PolyMet’s mine plan shows over 500 years of polluted water needing treatment
  • Mercury contamination in fish and wildlife
  • Expensive clean-up operations often fall to taxpayers
  • Mining and associated pollution, noise, and other serious impacts in areas near the Boundary Waters Canoe Area Wilderness that are important tourism and recreation areas