The Cabinet Mountains Wilderness & The Montanore Mine

A proposal to mine into the heart of the Cabinet Mountains Wilderness threatens grizzly bears, bull trout, and a treasured wild landscape. A summer visit gives a glimpse of places that could be forever altered by the Montanore Mine.

Hikers explore lush cedar forests in the East Fork Bull River drainage of the Cabinet Mountains Wilderness.
Hikers explore lush cedar forests in the East Fork Bull River drainage of the Cabinet Mountains Wilderness. (Katherine O'Brien / Earthjustice)

Update: August 15, 2017 On behalf of a coalition of conservation groups, Earthjustice has filed a lawsuit asking a state district court judge to overturn a water pollution discharge permit for the Montanore Mine project. More details.

A plan to develop a massive silver and copper mine beneath the Cabinet Mountains Wilderness in northwest Montana threatens to transform one of the region’s wildest places for centuries to come.

The proposed Montanore Mine would operate for up to two decades, extracting 20,000 tons of ore each day from tunnels bored beneath the wilderness. The project would also require construction of miles of high-voltage electric transmission line, an impoundment to store up to 120 million tons of mining waste, a wastewater treatment plant, and the paving of roads and clearing of trees.

A 35-mile expanse of glaciated peaks, the Cabinet Mountains is an intact wild ecosystem.

The region supports a diversity of native wildlife including mountain goats, bighorn sheep, pikas, wolverines, moose, elk, deer, wolves, mountain lions and Canada lynx.

And the Cabinet Mountains provide one of the region’s last remaining strongholds for bull trout and grizzly bears—both of which are threatened with extinction and protected by the Endangered Species Act. The grizzly bear population in the Cabinet Mountains and adjacent Yaak valley is one of only five populations remaining in the lower-48 United States. It is essential for the species’ recovery.

Flowing through the Cabinet Mountains are some of the purest waters left in the United States.

Logging, mining and construction of dams and roads have already irreparably damaged bull trout habitat throughout the region. But the streams originating in the Cabinet Mountains still support some of the last viable populations of migratory bull trout in the region, essential to bringing back the species.

The process of extracting silver and copper will pollute bull trout habitat with sediment and with water that is too warm for bull trout, and make reaches of wilderness streams run dry.

The mining company’s own consultants predict the mine’s operations will diminish flows in overlying wilderness rivers and streams—for more than 1,000 years.

In 2014, the U.S. Fish & Wildlife Service estimated that the Cabinet Mountains grizzly bear population had dropped as low as 21 bears, making it highly vulnerable to extinction.

Because the Cabinet Mountains grizzly bear population already is hanging on by a thread, every bear counts.

The killing of even a single bear would increase the population’s risk of extinction.

The Montanore Mine project would bring more than 800 people into the heart of grizzly bear habitat, greatly increasing the threat that grizzly bears will be killed due to poaching and conflicts with humans. In addition, the U.S. Fish & Wildlife Service found that the Montanore Mine would displace up to three quarters of the adult female grizzly bears from their preferred habitat.

Overall, the agency found that the mine would cause substantial and irreparable damage to threatened species and their habitats.

Yet in March 2014, the Fish & Wildlife Service released biological opinions for bull trout and grizzly bears that gave the mine a green light, contrary to the agency’s own findings about the project’s effects. Earlier this year, the U.S. Forest Service also approved the mine in reliance on the flawed biological opinion.

Earthjustice took the U.S. Fish & Wildlife Service and the U.S. Forest Service to court to enforce Endangered Species Act protections for grizzly bears and bull trout in the Cabinet Mountains.

Representing Save Our Cabinets, Earthworks and Defenders of Wildlife, Earthjustice filed a lawsuit in federal district court in Montana to overturn the agencies’ conclusions that the mine would not endanger the survival or recovery of grizzly bears or bull trout.

Resources on this legal case

“Every analysis of the Montanore Mine has shown that it will inflict irreversible damage on the Cabinet Mountains, ” says Katherine O’Brien, the lead attorney on the case. “Our state and federal agencies’ disregard of that evidence and insistence on pushing through the mine approval, whatever the cost, is irresponsible and unlawful.”

“If we are going to fulfill the promise offered by the Endangered Species Act, we cannot let our last, best places for threatened wildlife wind up on the rubble pile.”

What’s Happening Now: On August 15, 2017, Earthjustice filed a lawsuit, asking a state district court judge to overturn a water pollution discharge permit for the Montanore Mine project. The lawsuit argues, among other things, that the Montana Department of Environmental Quality acted illegally by omitting essential pollution-control requirements from the permit and relying on an outdated pollution authorization issued in 1992 to a different company for a different project to allow Montanore Minerals Corp. to evade Montana’s legal protections for high-quality waters.

“The Department of Environmental Quality should not allow out-of-state companies to use Montana’s prized streams as their industrial waste receptacle,” said Earthjustice attorney Katherine O’Brien.

Earlier in May, U.S. District Judge Donald Molloy issued a ruling in the lawsuit brought by Earthjustice on behalf of Save Our Cabinets, Earthworks, and Defenders of Wildlife. In two decisions, Judge Molloy ruled that the Fish and Wildlife Service and Forest Service violated the Endangered Species Act, Clean Water Act, National Forest Management Act, and National Environmental Policy Act in approving the Montanore Mine. The court rulings invalidate the approvals issued by the government agencies in 2014 and 2016, concluding, among other things, that the Forest Service’s action “puts the proverbial cart before the horse” in approving mine development despite prohibited impacts to wilderness waters.


The Northern Rockies Office is located in Bozeman, Montana.

Wild lands and wildlife that have been eliminated from much of the world still exist in the Northern Rockies region. Earthjustice’s attorneys take on cases that focus on protecting large, intact ecosystems, and seek to build ecosystem resilience by reducing pressures caused by oil and gas development, logging, road building, and off-road vehicle traffic. Learn more.