Protecting Voyageurs’ Waters from Sulfide Mine Pollution
Voyageurs National Park spans 218,000 acres, including 84,000 acres of water. This rich aquatic ecosystem is home to loons, snapping turtles, wood frogs, otters, and 53 fish species, including lake sturgeon, walleye, and smallmouth bass. Park wildlife depends on clean, healthy water to thrive.
Each year, the water-based park attracts 240,000 visitors to enjoy activities like kayaking, swimming, boating, and fishing. Outdoor recreation and tourism play a vital economic role, contributing $19 million annually to the local economy, supporting more than 300 jobs.
The lakes and wetlands that define Voyageurs National Park remain under threat from proposed sulfide-ore mining across northern Minnesota. While recent federal action has paused some projects, the fight to protect our watershed is far from over.
In 2023, the federal government enacted a 20-year moratorium on new mineral leasing across 225,000 acres of the Superior National Forest, an important step in protecting the Boundary Waters and the Rainy River watershed.
However, this protection is temporary and incomplete:
Mining companies continue to pursue projects on state and private lands
Legal challenges seek to reverse federal protections
New proposals (like the Tamarack nickel project) are advancing elsewhere in Minnesota
Federal legislation has been introduced that could reinstate canceled leases near the Boundary Waters
Without permanent protections, the waters flowing into Voyageurs remain at risk.
Why Sulfide Mining Threatens Voyageurs
Sulfide-ore mining for copper, nickel, and other metals is fundamentally different from traditional iron mining. When exposed to air and water, sulfide ore produces sulfuric acid, which can leach toxic metals into nearby waters.
This process, known as acid mine drainage, can:
Pollute lakes and rivers for decades or centuries
Release toxic metals like mercury, arsenic, and lead into ecosystems
Harm fish, wildlife, and human health
Threaten downstream waters, including Voyageurs National Park
Voyageurs sits at the downstream end of the Rainy River watershed, meaning pollution from upstream mining would inevitably flow through the park.
Take Action
We have a critical opportunity to protect the waters that define Voyageurs. Decisions currently under consideration in Congress will help determine whether sulfide-ore mining is allowed upstream of the park.
In January 2026, the U.S. House passed H.J. Res. 140, a measure that would overturn the 20-year federal mineral withdrawal affecting parts of the Superior National Forest within the Rainy River watershed.
The resolution is now under consideration in the U.S. Senate. If enacted, it could reopen the possibility of sulfide-ore mining in areas where activities were previously paused to evaluate long-term water quality risks.
Contact your U.S. Senators to ask them to oppose H.J. Res. 140 and protect Voyageurs National Park from sulfide-ore mining in the Rainy River watershed
Support long-term, durable solutions that provide clarity for both resource development and water protection
Participate in public comment opportunities related to sulfide-ore mining proposals
Stay informed and engage others in your community
Thoughtful, informed input from the public plays an important role in shaping policies that affect these waters for generations to come.
Timeline: Sulfide-Ore Mining Proposals in the Rainy River Watershed
Recent advocacy has made a difference:
Cancellation of key federal mining leases near the Boundary Waters
A 20-year mineral withdrawal protecting federal lands
Increased public awareness and engagement
But mining proposals continue to emerge, and protections can be reversed. Some policymakers are actively working to reopen these areas to mining. This is a critical moment.
Now: U.S. Senate considering the resolution; outcome will shape whether sulfide-ore mining can move forward upstream of Voyageurs
January 2026: U.S. House passes H.J. Res. 140 to overturn the mineral withdrawal
2024–2025: Ongoing legal and legislative efforts to reverse or modify protections
2023: 20-year mineral withdrawal enacted to study long-term risks of sulfide-ore mining
2016–2022: Federal leases issued, then canceled following environmental review
2015: Voyageurs Conservancy and the National Parks Conservation Association commission a hydrology study to document the risks to Voyageurs National Park if sulfide mining development occurs in the Rainy River Watershed.
A Watershed Report
Findings from a 2015 study commissioned by Voyageurs Conservancy and the National Parks Conservation Association document risks to Voyageurs National Park:
Report Summary: A Watershed Moment (PDF)
Full Report: Potential Metals Mining and Voyageurs National Park, Tom Myers, PhD (PDF) - Map: Voyageurs Watershed
“Voyageurs is at the downstream end of its watershed, so everything entering the watershed passes through it before reaching Canada. Mercury contamination, leaching of arsenic, or other acid mine drainage will pass through the park.”
A Water-Rich Landscape at Risk
Northern Minnesota is one of the most water-rich landscapes in North America. Thousands of lakes, wetlands, and interconnected waterways define this region—and make it uniquely vulnerable. Scientific studies and real-world examples show that sulfide mining and water do not mix safely, especially in areas with abundant surface water. Even small leaks or failures can have long-term, irreversible impacts on ecosystems, recreation, and local economies.
Voyageurs National Park encompasses:
World-class fishing, paddling, and wildlife habitat
Local businesses and tourism economies
Cultural and ecological connections across Minnesota and Ontario
Pollution from sulfide mining could undermine all of this—impacting not just the park, but communities across the watershed.
Voyageurs Conservancy is committed to ensuring that our National Park remains protected for its surrounding communities, park visitors and future generations. The effects of acid mine drainage from sulfide (copper-nickel) mining in our watershed leave the potential for permanent damage to Voyageurs National Park’s waters and wildlife. The Conservancy is carefully monitoring this issue and the potential impacts to Voyageurs.
