The Tulsequah Glacier meanders down a broad valley in northwest British Columbia, 7 miles from the Alaska border. At the foot of the glacier sits a silty, gray lake, a reservoir of glacial runoff. The lake is vast, deeper than Seattle’s Space Needle is tall. But it didn’t exist a few decades ago, before 2 miles of ice had melted.

On an overcast day, a helicopter carrying three salmon scientists zoomed up the valley. As it neared the lake, the pilot banked to the right and flew over the south side of the basin, whirring over a narrow outlet where it drains into the Tulsequah River. He landed on a beach of small boulders and the researchers clambered out one by one.

“We don’t think there are fish here yet,” said one of them, Jon Moore, an aquatic ecologist at Simon Fraser University in Vancouver. “But there will be soon.” 
The lake, so new to the landscape that it doesn’t have an official name, is still too cold and murky for salmon. But that’s likely to change soon: As the Tulsequah Glacier above it retreats, the lake is getting warmer and clearer, becoming a more attractive environment for migrating fish. “It’s going to be popping off,” Moore said.

It’s among hundreds of ice-fed lakes, rivers, and streams in Alaska and western Canada that could turn into prime fish habitat as the planet gets hotter. These new salmon grounds could help counteract other threats to the fish from climate change, such as warming seas and drought. And they could bolster a commercial fishing industry that generates millions of dollars for the state each year. 

The disappearance of glaciers is also creating opportunities for the multibillion-dollar mining industry. Like migrating salmon, mineral exploration companies are moving quickly into areas exposed by melting ice, hoping to strike the next big lode. 

With gold prices booming and demand soaring for copper, a metal necessary for making solar panels and electric cars, mining corporations have backed a number of major projects in the region. The Canadian government is paying for roads and power lines to improve access to them.

This mineral rush promises jobs and revenue for some towns and First Nations in northern Canada. But it’s troubling to many Alaska fishermen, environmental advocates, and Indigenous leaders living downstream, near several salmon-rich rivers that start in Canada and head west across the international border. The Tulsequah River is a major tributary of the Taku River, which runs about 50 miles from British Columbia’s Coast Mountains to the Pacific Ocean just south of Juneau, Alaska. The Taku supports iconic runs of sockeye and coho salmon that power commercial fishing businesses in both countries. In 2023, Moore and other researchers warned in the journal Science that, barring key policy reforms, future mines could impair future salmon habitat in glacier-fed watersheds like the Tulsequah and Taku. 

Alaska Native leaders have called on British Columbia’s provincial government to clamp down on mining in the region, and some First Nations are working to restrict mineral exploration and development in their traditional territories. But Canadian officials largely support the proposed mines, and the Trump administration has stayed quiet on the issue of mining near the border, though Canada’s mineral riches have reportedly attracted President Donald Trump’s interest.

On the Tulsequah River, the stakes are clear. A few miles downstream from the new lake, a ribbon of rust-colored water flows into the waterway: acid runoff from a former gold mine. Contaminants from the Tulsequah Chief mine have been flowing into the river ever since the operation shut down in the 1950s. Alaska’s elected officials, salmon advocates, and Indigenous nations have urged British Columbia’s government and mining companies to clean it up for decades without success. 

The pollution is confined to just a short stretch of river — and fish, including some salmon, still swim in the waters below it. Still, environmental groups often cite the uncontained acid drainage as an example of what can go wrong with mining.

The Tulsequah Chief mine stopped producing gold more than 60 years ago but still leaks acid drainage into the Tulsequah River. Environmental groups often cite the pollution, which is confined to a relatively short stretch of river, as an example of what can go wrong with hard rock mining.
Max Graham / Grist

A small Vancouver-based company, Canagold, wants to reopen and expand a different gold mine on the other side of the river from the shuttered Tulsequah Chief. The opening of a new mine could coincide with the expansion of salmon grounds in the upper Tulsequah watershed. Moore and his colleagues hope that their projections of emerging fish habitat in the lake that drains into the Tulsequah River will be incorporated into environmental assessments for new mining proposals like Canagold’s. 

In some watersheds, nearly all of the projected habitat lies within a few miles of mining claims. Even though no fish swim in those lakes and streams now, that could change in just 20 or 30 years, the lifespan of a typical mine, said Chris Sergeant, a freshwater ecologist at the University of Washington who works with Moore on the Tulsequah and nearby rivers. Sergeant wants regulators to consider this prospect before they approve a mine. Accounting for this future habitat is especially important, he added, “because there just aren’t that many places where salmon are doing well.”

News articles describing the effects of climate change on salmon usually tell an alarming story: Fast-warming oceans and rivers are threatening an iconic fish that thrives in cold water, while record droughts are drying up their streams. 

Some of these grim effects were on display last September about 250 miles south of the Tulsequah Glacier at Meziadin Lake, a long basin ringed by hemlocks and firs, near the small mining town of Stewart, British Columbia. It’s one of the province’s most abundant spawning areas for sockeye salmon.  

Read Next

As salmon disappear, a battle over Alaska Native fishing rights heats up

In a typical year, hundreds of thousands of sockeye fill Meziadin Lake and the surrounding creeks. Two creeks that feed the lake, Hanna and Tintina, have a reputation for being especially prolific. Each September they swell bank to bank with sockeye, splashing, spawning, and dying en masse. These runs can be so plentiful that wolf packs and grizzly bears sometimes catch fish within feet of each other.

But last year, during what should have been the peak of Tintina’s sockeye run, only a handful of salmon made it upstream. After a summer of high temperatures and drought, the creek was flowing at its lowest level in recent history, said Kevin Koch, a fish and wildlife biologist who works for the Gitanyow Hereditary Chiefs, a First Nation whose traditional territory encompasses the area. Below a highway bridge, the slow, sad creek looked more like a pond. A thick mat of algae blanketed its bottom. 

Two years ago, “you would have seen hundreds of fish,” Koch said, looking down from the bridge on a crisp day last fall. He saw none.

Hanna Creek, a couple miles away, also trickled at a historic low, according to Koch — though some ruby-red fish still wriggled in its mucky water. 

What’s happening at Hanna and Tintina is only part of the picture, though. As the planet warms, a third creek that flows into Meziadin Lake has also transformed in a stunning way, but one that’s actually helping salmon.

For a long time, Strohn Creek gushed out of a huge glacier, and hardly any sockeye swam in its turbid water. While glacial runoff helps make some streams more habitable for salmon by keeping them cool, it also can have the opposite effect: Streams that flow directly from glaciers are often near freezing, too cold even for the cold-loving fish. And they’re full of silt, which blocks the sunlight that forms the basis of the food chain. Salmon eat insects and tiny marine animals called zooplankton; the insects and zooplankton eat algae; and the algae feeds off the sun.

As the glacier above Strohn shriveled up and retreated from a mountain pass in the second half of the 20th century, its runoff started to drain down the other side of the Coast Mountains, away from Strohn Creek. Without a torrent of ice melt, the creek lost its silt and warmed up enough that, after a few decades, salmon now spawn there in the thousands. “There was this huge shift happening before our eyes,” said Naxginkw Tara Marsden, who directs the Gitanyow Nation’s sustainability program. 

Approaching Strohn Creek to observe the peak of last year’s sockeye run, Koch brushed aside alder branches and yelled to alert lurking brown bears. 

“This spot is one of the most pain-in-the-ass spots for grizzlies, where I’m taking you,” Koch said. “So sorry about that.” 

The stream came into view. Half-eaten fish carcasses were strewn along its banks, and dozens of bright-red salmon splashed in its shallow blue waters. Their tails slapped the surface as they fought against the current.

In some years, more sockeye return to Strohn than to Hanna or Tintina Creek. Scientists think it could be a bellwether: There are countless creeks like Strohn across Alaska and western Canada — glacial streams that could transform into salmon havens as the ice above them melts. Fish are turning up in these new spots surprisingly quickly. Hundreds of miles from Strohn Creek, scientists found pink salmon in a stream in Alaska’s Glacier Bay National Park less than a decade after it emerged in the wake of a receding glacier.

According to a paper in Nature that Moore co-authored in 2021, nearly 4,000 miles of new salmon streams could appear in Alaska and northwestern Canada by the end of the century. The gains could be “enormous,” Moore said.

And that estimate — one of the only published projections of emerging salmon habitat near glaciers — doesn’t account for new lakes, like the unnamed one below the Tulsequah Glacier, or streams or rivers that already support a handful of salmon but could boast a lot more. By one rough, unpublished estimate from Moore and his colleagues, the extent of lake habitat accessible to salmon in the 4.5-million-acre Taku River watershed could double over the next 100 years.

This all sounds promising for a species under siege, but salmon researchers warn that the region’s mining boom could stand in the way. 

In the Nass River watershed, which encompasses Strohn Creek and Meziadin Lake, some 99 percent of emerging salmon habitat is within roughly 3 miles of mineral claims, according to Moore and Sergeant’s study. 

Around the same time that Gitanyow leaders first witnessed the salmon bonanza in Strohn Creek, about eight years ago, they also discovered that companies looking for valuable minerals had staked mining claims in the mountains upstream, including beneath some of the small glaciers and snowfields that drain into the creek. 

It was a glimpse of the mineral rush that now spans hundreds of miles of British Columbia’s Coast Mountains, from Meziadin Lake in the south to the Tulsequah Glacier in the north. Nicknamed the Golden Triangle for its metal-rich rocks, the region first lured prospectors 150 years ago. They led horses across glaciers, and tunneled thousands of feet into the ice using steam-powered equipment and sleds. 

Today, they travel by truck and haul drills by helicopter. Driven by record-high gold prices and demand for copper, northwest British Columbia drew some $250 million in investments in mineral exploration last year, accounting for more than 60 percent of the industry’s total expenditures across the province, according to British Columbia’s Ministry of Mining and Critical Minerals. A government report in 2022 estimated that more than $900 billion worth of metals could be sitting beneath the Golden Triangle. That figure stands at well over $1 trillion with today’s record-high gold prices.

The mining industry’s mark on northwest British Columbia is hard to miss. Ore trucks thunder along the region’s main highway, hauling loads from a large copper mine, built a decade ago and now set to expand. A hefty 200-mile transmission line skirts the same road: a $500 million project developed in 2014 largely to power new mines with hydroelectricity. Large signs bearing the names of mining companies — Teck, Newmont, Skeena Resources — stand beside gated gravel roads that spur off the two-lane highway.

Deeper in the Coast Mountains, the gold and copper rush happens mostly out of sight, across roadless, heavily glaciated terrain. Roughly one-fifth of all the mining claims in northwest B.C. are covered by glaciers, according to a report released last year by the Environmental Investigation Agency, a global watchdog group. As those glaciers melt, they’re exposing outcrops of gold and copper that are luring mineral companies, whose geologists then drill into bedrock freshly exposed to the sun after thousands of years under ice. Mining companies are even staking claims beneath glaciers, poised to move in as soon as the ice melts. 

“The glacier might melt at some point, and you want to be the first person” to see the rocks beneath it, said Matthew Reece, a U.S. Forest Service geologist based in Juneau who oversees mining in Alaska’s national forests.

Vancouver-based Scottie Resources Corp., one of the companies with claims in the mountains near Strohn Creek, has a few prospects that could attract more investors as nearby ice thaws. Hoping to find more gold, the company is drilling into the rock near a long-shuttered underground mine in a mountain partially covered by a glacier. Old tunnels, built decades ago, allowed miners to dig up just a sliver of the deposit. Scottie Resources is discovering more gold as the ice above it melts, according to Thomas Mumford, the company’s vice president of exploration. 

“We are literally the first humans to look at those rocks,” Mumford told Grist.
Not far from Scottie’s claims, another small Canadian firm, Goliath Resources, recently discovered gold and copper in a small island of rock surrounded by a massive ice field. “I get the question, ‘Why hadn’t someone drilled it before?’” Roger Rosmus, Goliath’s chief executive, said in an interview posted on YouTube last year. “It was actually buried under the glacier and permanent snowpack, which are no longer there. We got lucky.”

Reviewing filings from Canadian securities regulators, corporate presentations, and marketing materials for investors, Grist identified more than 20 companies that tout the promise of melting glaciers in Alaska and British Columbia. That number, likely an undercount, could grow as demand increases for metals like copper, and as more ice disappears. Last year, a private company named B-ALL Syndicate, partly funded by Goliath, launched a “large-scale exploration and prospecting program” aimed specifically at melting snow and ice across the region. 

Most of these companies, including Goliath and Scottie, are small and based in Canada, where they can take advantage of generous tax policies. They tend to be funded by investors who like taking risks, or are eager for tax write-offs. Just a tiny fraction of prospects ever become producing mines. 

Government support can help boost their chances, though — and the industry in northwest British Columbia has received a good deal of it over the past decade. Just last year, Canada’s federal government and British Columbia’s provincial government committed $140 million to upgrade the region’s only major road, Highway 37, explicitly to support production of “critical minerals.” Those are elements, like copper, that Canadian officials have deemed essential for national security and renewable energy.Some Alaskans, including the state’s Republican U.S. senators have worried that funding for Canadian mines could also come from the U.S. government, potentially boosting mining upstream from Alaska and endangering the state’s fishing industry. The Biden administration directed tens of millions of dollars to mineralprojects in Canada, also in the name of national security and clean energy as it considered Canada akin to a domestic source.

Read Next

A guide to the 4 minerals shaping the world’s energy future

The Trump administration has yet to say if that funding will continue. Trump himself has signaled strong support for mining on the American side of the border: On his first day in office in January, he signed an executive order to develop Alaska’s minerals and other resources “to the fullest extent possible.” 

But Trump has also tried to unravel the 2022 Inflation Reduction Act, which established tax credits and other financial incentives that have spurred mining in both the U.S. and, indirectly, Canada. And some analysts have warned that certain tariffs Trump has threatened to put on Canadian goods could hamper Canada’s mining industry and the U.S. mineral supply chain.

Senator Lisa Murkowski, a Republican from Alaska, has called for a halt in sending U.S. taxpayer dollars to Canadian mines, citing past pollution, like the old, acid-leaking gold mine along the Tulsequah River. “I join many in Southeast Alaska who do not believe that our pristine waters are adequately protected,” she wrote to Biden in 2023. 

Murkowski’s plea came even though she has supported mining elsewhere in the state. Earlier this year, she praised Trump’s Alaska-focused order.

Many Alaska Native leaders have also been lobbying against mining in Canada upstream from their communities. Worried about threats to salmon and other traditional food sources, the biggest Indigenous nation in Southeast Alaska — the Central Council of the Tlingit and Haida Indian Tribes of Alaska — wants the B.C. government to put a hold on mine permitting in transboundary watersheds until Canada and the U.S. agree to a framework for resolving mining disputes in the region. The council has also asked for a permanent ban on storing waste behind large dams above salmon-bearing rivers that cross into Alaska.

Are critical minerals “more critical than our lives?” Richard Peterson, president of the Tlingit and Haida government, asked an audience of tribal citizens, environmental advocates, and government officials at a conference in Juneau last year. “More critical than the fish?”

Government regulators and industry representatives contend that mining can be done safely, without harming salmon. All mining in British Columbia “is subject to a robust environmental review process, whereby any potential impact to wild salmon habitat must be avoided and mitigated,”according to a spokesperson for the province’s Ministry of Mining and Critical Minerals. Regulators in the province ensure that any activity in mountain watersheds “adheres to the highest standards of environmental protection,” he wrote in an email.

The mining industry is also a vital source of jobs and revenue for two First Nations in the region: the Nisga’a and Tahltan. Over the past two decades, those nations have made deals with mining corporations for production royalties or cash payments, as well as commitments to hire their citizens. Tahltan leaders have also signed a series of agreements with the provincial government that gives the Tahltan a voice in regulatory decisions on a few mining projects in the nation’s traditional territory.

While small Canadian companies have been scouring rocks near receding glaciers, publicly traded mining giants have also been investing in prospects across Alaska and B.C. One of North America’s biggest, Newmont Corp., bought a company with two operating mines in northwest B.C. in 2023, and it’s now seeking to develop a third, in partnership with another mining giant, Vancouver-based Teck Resources. 

That development, Galore Creek, would be a massive open-pit copper and gold mine 25 miles from the Alaska border, in an area ringed by receding glaciers. In 2023, Teck and Newmont’s geologists discovered minerals in rocks there that had been covered by ice a few years before. Last year, Canada’s department of natural resources handed the companies $15 million to build a key access road to a proposed processing site.

Galore Creek’s backers are marketing the mine as a climate solution: It’s sitting on an estimated 12 billion pounds of copper, enough to make it one of North America’s biggest sources of the mineral. Since copper is great at conducting electricity, it’s especially useful for building energy equipment like solar panels and transmission lines. S&P Global projected in 2022 that demand for the metal would double by 2035. 

But Teck, Newmont, and other mining corporations that could benefit from copper subsidies aren’t just after copper. Most of them are also looking for gold, which is used mainly for jewelry and in financial markets and considered less important for developing renewable energy than copper and other minerals like lithium and cobalt. The Biden administration didn’t consider gold “critical” but Trump promoted it along with dozens of other minerals in an executive order he signed earlier this year to spur mining nationwide. In addition to the copper that Galore Creek’s owners like to advertise, their mine could yield some 9 million ounces of gold, worth roughly $29 billion at current prices. 

Critics argue that huge corporations shouldn’t be getting clean energy subsidies to dig gold out of the ground. The mining industry’s marketing of critical minerals, while miners largely hunt for gold, is “one of the biggest greenwashing efforts on Earth,” said Mary Catharine Martin, a spokesperson for SalmonState, an Alaska-based mining watchdog group.

One company that’s focused primarily on gold is Canagold, with its proposal to resurrect a mine along the Tulsequah River, some 40 miles from Juneau and about 8 miles downstream from the future sockeye lake that Moore and Sergeant are studying. Canagold bought the site in the 1990s and still hasn’t started producing. Soaring gold prices, driven by Trump’s tariffs and global economic uncertainty, however, have injected new life into the project, known as New Polaris. Canagold has proposed shipping construction materials by barge up the Taku River from Alaska and building an airstrip where the company would load ore concentrate onto planes to fly out of the mountains.

The success of New Polaris hinges in part on a unique agreement between Canagold and the Taku River Tlingit First Nation, whose traditional territory encompasses the site and the Tulsequah River. Their agreement, announced in 2023, gives the nation a say — by a vote of its citizens — in whether the mine gets built. 

The Taku River Tlingit nation is also a key partner on Moore and Sergeant’s salmon research: The nation’s fisheries coordinator, Mark Connor, co-authored the 2023 policy analysis in Science that first noted the prevalence of mining claims near future salmon habitat. (Marsden, with the Gitanyow nation, was also a co-author on that paper.)

To keep emerging fish habitat intact, Taku River Tlingit established their own protected area, prohibiting mining across 60 percent of the Taku River watershed. In the other 40 percent, the First Nation allows some development with its approval. New Polaris sits in that zone, and the nation’s leaders are confident that Taku River Tlingit citizens will have a say in whether a mine ultimately gets built. 

“We already have verbal agreements with the company that they will not proceed with a mine should our citizens, or the majority of our citizens, not agree with that,” said Rodger Thorlakson, Taku River Tlingit First Nation’s lands and resources manager. 

Canagold, however, doesn’t have similar agreements with Indigenous governments downstream in Alaska. Clarence Laiti, president of the Douglas Indian Association in Juneau, said he’s “very, very concerned” about mining in the Taku River watershed. For decades, Laiti caught salmon for a living at the mouth of the Taku, some 30 miles below New Polaris. “It’s everybody’s river,” he said.

On the beach along the upper stretch of the Tulsequah River, 8 miles upriver from New Polaris, the three salmon scientists — Sergeant, Moore, and Brittany Milner, one of Moore’s doctoral students — unraveled a 30-foot seine fishing net. To learn more about the habitat, they catch, record, and release fish in dozens of spots along the river. They had never seen salmon this far up the river, this close to the new lake. They still sample the spot, though, because they think fish could appear any year as the water warms.

Milner grabbed one end of the long net and stood on shore. Moore took the other end and waded into the water, slowly walking in a circle to corral any fish that might have been lurking. Once again, they caught nothing. 

About a week later, the researchers flew back to check a dozen small, cylindrical minnow traps that they had set in the lake itself. To their astonishment, they found a Dolly Varden, a common species of char, the first fish they’d ever seen in the new lake. 

“It was kind of surreal,” said Milner, who had set the trap in a shallow area near the mouth of a stream that was slightly warmer than the rest of the lake. Dolly Varden, which can tolerate very cold water, often move into glacial lakes and streams before other species. 

“I’m assuming the fish was just in the lake swimming around and was able to find this pocket of a little bit warmer water,” Milner said. “I was really stoked.”

The rest of the traps came up empty: still no salmon. But to Milner and the other scientists, that one Dolly Varden sure looked like a sign of more to come.