There’s no such a thing as a truly pristine landscape — humans have, over millennia, shaped every environment on Earth — but the Boundary Waters wilderness of northeastern Minnesota comes pretty darn close.

Stretching across more than a million acres near the Canadian border, about four hours north of Minneapolis, the Boundary Waters is a messy patchwork of lakes, streams, and islands with hardly any human infrastructure. At dawn, loons slice through the placid water and, come nightfall, bright stars splatter the dark sky.

The natural beauty of the Boundary Waters — a federally protected wilderness area — is a magnet for tourism, an enormous economic engine for the region. The Boundary Waters is not only the most visited wilderness area in the country, but also home to federally threatened species like the gray wolf and the Canada lynx.

It’s for this reason that many environmental advocates are worried about a proposed mine just outside the southern edge of the Boundary Waters. A company called Twin Metals Minnesota — a subsidiary of the Chilean copper giant Antofagasta — wants to mine copper, nickel, and other metals deep underneath the wet Earth. And earlier this year, Congress and President Donald Trump removed a major obstacle that had stood in its way: The House and Senate overturned a Biden-era mining ban in the region, allowing Twin Metals to revive its mining push within the watershed.

Environmental advocates warn that a metals mine could be disastrous for the unique Boundary Waters ecosystem. Though mining and other extractive industries are prohibited inside the Boundary Waters, the region’s hydrology is such that any pollution from the mine would likely flow into the wilderness area, potentially harming its forests, wildlife, and the livelihoods of Native Americans, who use the area to fish, hunt, and harvest wild rice.

And the thing about mines, critics say, is that they nearly always pollute.

“It’s not a matter of if this mine is going to pollute, it’s a matter of when,” said Ingrid Lyons, executive director of the advocacy group Northeastern Minnesotans for Wilderness, which leads a campaign called Save the Boundary Waters.

Twin Metals says these concerns are largely rooted in misinformation and it can mine in an environmentally safe way. Like other mining projects seeking approval, this one would have to meet both federal and state environmental safeguards before opening — and Minnesota’s are particularly strong. The company also defends the project on a different kind of environmental grounds, pointing out that the world needs more metals like copper, nickel, and cobalt to build clean energy technologies, such as batteries for electric cars — which is true. If those metals don’t come from Minnesota, they might just come from other countries with less rigorous environmental regulations.

The upshot is that what may sound like a simple narrative — environmentalists versus a mine — highlights a more complex reality. Mining isn’t inherently bad; yet, it always comes with tradeoffs. The question facing Minnesota, where there’s still a path to ban copper mining near the Boundary Waters, is whether the costs will be worth it.

While the Boundary Waters is famous for its surface lakes, streams, and forests, it sits atop one of the world’s largest unexploited deposits of copper and nickel, known as the Duluth Complex. It’s these materials that Twin Metals is after.

According to Twin Metals, miners would excavate and crush ore — metal-rich rock — as far as 4,500 feet down and, then, send it up to the surface. There, they’d remove compounds containing copper, nickel, and other minerals, which they’d ship elsewhere to be refined into usable metals. The company said it would put some of the leftover rock, known as tailings, back underground. The rest would go into a pile on land nearby.

Twin Metals has been pursuing this planned mine for more than a decade, and it said it’s plowed some $650 million into it. In recent years, however, the project has hit a number of roadblocks.

In 2022, the Biden administration cancelled Twin Metals’s two mineral leases (which had given the company a right to explore and mine in certain areas but not approval for specific projects). And, in early 2023, the administration put a 20-year pause on approving new leases near the Boundary Waters in the region where Twin Metals had been planning to mine. “With an eye toward protecting this special place for future generations, I have made this decision using the best-available science and extensive public input,” then-Interior Secretary Deb Haaland said in a statement announcing the decision.

It was that temporary ban that was recently overturned. Congressional Republicans — led by Minnesota Rep. Pete Stauber — found what is essentially a loophole, through an obscure law called the Congressional Review Act, to not only undo the ban but also to prevent future administrations from issuing similar protections without an act of Congress.

This move does not reinstate Twin Metals’s two federal mining leases. The company had previously challenged the lease cancellations, back in 2022, and it’s still waiting on a decision from the courts. Congress is also considering a bill that would re-issue those leases to Twin Metals. Should the company acquire leases to mine, the project would then be subject to a review by federal and state agencies, both of which have the authority to block the project. Even with federal approval, the Minnesota Department of Natural Resources, a state agency, could decide not to grant the company a permit to mine.

Twin Metals says, perhaps unsurprisingly, that its mine will be exceptionally clean. The mine would be underground, the company said, so it would have only a small surface footprint, including a processing facility about the size of a Super Target.

The company also claims that its modern approach won’t produce a water pollutant — common among mines — called acid rock drainage. Metal in the ore is bound to compounds called sulfides. When sulfides react with air and water, they can produce sulfuric acid, which is toxic to plants and animals and can leach heavy metals, such as arsenic, out of rock.

“Twin Metals Minnesota is focused on responsibly developing the minerals in the Duluth Complex,” Kathy Graul, a spokesperson for Twin Metals, told Vox. “Any proposed project in this region, including Twin Metals, must undergo a yearslong, multi-agency regulatory review before earning permits to begin construction of a mine.”

Environmental advocates and the academic researchers I spoke to are not convinced.

“If the mine is built, there would be runoff, there would be mine discharge, and that discharge would contain sulfate,” said Lyons, of Northeastern Minnesotans for Wilderness. “Because [Twin Metals] can’t present a credible argument otherwise, they attempt to distract from this main point by saying the drainage would not be acidic.”

Lee Frelich, a forest ecologist at the University of Minnesota who has studied the impacts of sulfide mining, shared similar concerns. Harmful chemicals released from the mined rock are likely to reach the Boundary Waters, where they can damage trees and aquatic animals, through complex, cascading effects. Sulfate pollution can also impair the growth of wild rice, a critical and sacred food resource for Indigenous peoples in the region, according to Emily Onello, a physician and medical researcher at the University of Minnesota Medical School Duluth.

Twin Metals, and those who support this mining project, recognize that mining in the past has created substantial environmental problems. But modern mines are cleaner and safer, they say. This one, they say, would be cleaner and safer.

That is almost certainly true. Environmental regulations are much stronger now than they were decades ago, when companies would often abandon unprofitable mines without cleaning them up. And if firms like Twin Metals want permits to mine, they’ll need to abide by them. “Projects must prove they can meet the stringent environmental standards that have long been in place in Minnesota before moving forward,” Graul told Vox.

But what no one can really guarantee is that there would be no pollution.

“New mines are going to be cleaner, they’re going to be better, they’re going to be better permitted — but they also are going to have impacts,” said Dustin Mulvaney, a researcher at San José State University who studies the impacts of resource use.

That much was made clear in a 2022 report by the Interior Department: “Hardrock minerals mining of sulfide-bearing rock, no matter how it is conducted, poses a risk of environmental contamination due to the potential failure over time of engineered mitigation technology.” In other words, even mining companies that are thoughtful about their footprint run the risk of polluting the environment. (Many of the report authors are still government employees.)

So, it seems fair to say that there is indeed some risk of pollution, especially considering the rise in extreme floods and other weather events that put infrastructure at risk. Mine drainage is also a problem that can last for decades or even centuries, long after the companies that create the problems leave.

The question, then, becomes: Is that risk worth it?

Proponents of the mine say they have to mine here — that this is where the minerals are, and those minerals are critical to our essential technologies. “We are blessed with these minerals right under our feet,” Congressman Stauber told me, adding that he’s confident that the mine won’t pollute should it get approved by the state.

Julie Lucas, executive director of mining advocacy group MiningMinnesota, has repeatedly made the important point that we’ll need to produce more minerals for the energy transition. “Mining is fundamental to our lives today and more important than ever for our future,” Lucas, the former water resources director for Twin Metals, said in a 2024 commentary in The Minnesota Star Tribune. “We aren’t doing the Earth any favors by declaring a definitive ‘no’ against potential mining projects.”

What mining companies often don’t talk about, however, is whether there are less risky alternatives. “There is almost always a better place to build that infrastructure,” said Grace Wu, who studies the tradeoffs of clean-energy technologies at University of California Santa Barbara.

Certainly, there are other places to mine copper in the US, Mulvaney said, most of which currently comes from Arizona. There’s also already an active nickel mine in Michigan. What’s more is that the US throws out a lot of copper each year; in 2023, for example, only about a third of post-consumer copper was recycled. The same politicians who are pushing for more mining, citing urgent supply needs, haven’t been addressing the lack of metals recycling, Mulvaney said.

“There’s no place that has to inherently be mined,” Mulvaney said.

The opponents I spoke to weren’t arguing that the US should export mining — and related ecological problems — to other countries, which often have less stringent health and environmental safeguards and law enforcement. But there are more acceptable places to mine in Minnesota, such as in watersheds that are already industrialized, they said.

There are only so many intact expanses of wilderness like the Boundary Waters left in the country, said Lee of University of Minnesota. The value they provide to future generations is infinite, he said, and dwarfs what we can gain from one mine.

Put another way: It’s not mining that’s the problem; it’s mining precisely here.

“It’s just the wrong place for this type of mine,” said Alex Falconer, a Democratic state Rep. in Minnesota who also works for the Save the Boundary Waters Campaign. “Society can pick and choose where mining should happen.”

Under the first Trump administration, for example, then-Interior Secretary Ryan Zinke announced a 20-year ban on hard-rock mining near Yellowstone National Park. At the time, Zinke, now a Montana representative and whose state includes a sliver of Yellowstone, said “there are places where it is appropriate to mine and places where it is not.”

What happens now is murky, though, it’s unlikely that the Trump administration will stand in the way of Twin Metals. (What might be helping their cause: A lobbying firm hired by the company was founded and chaired by Trump’s other former Interior Secretary, David Bernhardt.) That means they could get federal mining leases soon.

The fight then turns to the state, where Rep. Falconer is pushing a state bill that would prevent Minnesota regulators from issuing permits for copper mining in the Boundary Waters and its headwaters. Falconer says he hopes it will come to a vote early next year and — pending the results of the midterm elections — become law. “The watershed of the Boundary Waters is sacred to me,” he said. “It’s off limits.”

If efforts like this to block mining in the watershed fail, and Twin Metals starts digging up metals, Lyons says it will be a warning for other natural treasures across the US. “If something bad can happen in the boundary waters,” she says, “it can happen anywhere.”