For the First Time in Nearly a Century, Adult Winter-Run Chinook Salmon Are Swimming in California’s McCloud River

Video footage shows a female guarding her nest while several smaller males compete for positioning nearby

Sarah Kuta | Daily Correspondent

August 1, 2025

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For the first time in nearly a century, adult winter-run Chinook salmon have been spotted swimming in the McCloud River, a Northern California waterway.

On July 15, experts with the California Department of Fish and Wildlife confirmed reports of adult salmon in the river, according to a recent Facebook post. They also captured video footage of an adult female Chinook salmon guarding her nest, which biologists call a “redd.” It’s a depression in the gravelly riverbed that the fish makes with her body, turning on her side and sweeping away stones with her tail. Several smaller males, called “jacks,” were seen swimming nearby to compete for the chance to fertilize her eggs.

These salmon probably ended up in the McCloud River as a byproduct of conservation efforts that started in 2022, the department writes. That year, biologists from several organizations teamed up to incubate winter-run Chinook salmon eggs in the waters of the McCloud River, returning the fish to their historic spawning grounds that are chilled by snowmelt and cold springs above Shasta Dam.

As those eggs hatched and the salmon began to mature, they swam downstream. Biologists then captured many of the juveniles at collection facilities, so they could transport them around manmade barriers, like the Shasta Dam, that would prevent the fish from continuing their instinctive journey to the Pacific Ocean. Officials released the juveniles into the Sacramento River near Redding, California, so they could finish their journey to the sea.

However, some of the young salmon managed to avoid being captured. These fish ended up swimming downstream into Shasta Reservoir, where biologists suspect they spent at least a year. Eventually, those adult salmon headed back upstream to the McCloud River, where they’re being seen today.

The 2022 initiative was a collaboration between the California Department of Fish and Wildlife, the Winnemem Wintu Tribe, the United States Fish and Wildlife Service and the National Oceanic and Atmospheric Administration (NOAA) Fisheries.

“Adult salmon returning and spawning in the cool waters of their historic habitat off the increasingly hot Sacramento Valley floor is seen as critical to the recovery of winter-run Chinook salmon,” according to the Facebook post.

Winter-run Chinook salmon have been listed as endangered since 1994, and they’re among the ten marine species that NOAA Fisheries considers to be the most at risk of extinction in the near future. They are the only Chinook salmon that spawn in the summer, then migrate as adults to the Pacific Ocean in the winter, according to NOAA Fisheries. And they only live in one place: the upper Sacramento River and its tributaries.

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The fish have been struggling since the late 1930s, when crews constructed Shasta Dam on the Sacramento River. Since then, the dam (along with the nearby Keswick Dam) has blocked the salmon from swimming farther upstream to the cooler tributaries where they have historically spawned, including the McCloud River.

They must now lay their eggs below the dam, in the lower Sacramento River, where air temperatures average nearly 100 degrees Fahrenheit in the summer, per NOAA Fisheries. Since winter-run Chinook salmon spawn in the summer, this arrangement has been detrimental to their survival.

Officials have tried to help the fish by releasing chilly water from Shasta Reservoir into the Sacramento River every summer. They do so by maintaining what’s known as a “cold water pool” behind the dam. But during a statewide drought that lasted from 2012 to 2016, Shasta Dam lost its cold water pool. So, instead, officials released warmer water from the reservoir into the Sacramento River. The result was catastrophic: Between 95 and 98 percent of eggs and recently hatched winter-run Chinook salmon in the waterway died, according to NOAA.

Meanwhile, officials note that water temperatures above Shasta Dam in the McCloud River stayed cool during the drought. If the fish had been able to access their historic spawning habitat, more of their offspring likely would have survived.

Shasta Dam is not currently slated for removal, and it may even be enlarged under the Trump administration. So, instead, biologists are focused on reintroducing hatchery-raised, winter-run Chinook salmon above the dam.

These efforts are probably delaying the species’ extinction. But, to the members of the Winnemem Wintu Tribe, they’re far from ideal.

“The salmon that exist right now, they don’t know how to mountain climb, they don’t know how to go up waterfalls, because they’re blocked,” says Rebekah Olstad, salmon restoration project manager for the tribe, to the Guardian’s Cy Neff. “So, it’s generations and generations of eggs and salmon who don’t have those genes anymore to be wild.”

If removing Shasta Dam is not an option, then tribal members would like to see the construction of a fish passage that would allow the salmon to complete their seasonal migrations on their own.

It’s good news that adult salmon have been spotted in the McCloud River this summer. But there’s still “no way for them to get out back to the ocean,” and that’s a problem, tribal member Michael Preston tells the Guardian. “That’s the real salmon, right?” he adds. “They have to go to the ocean to come back.”

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Sarah Kuta is a writer and editor based in Longmont, Colorado. She covers history, science, travel, food and beverage, sustainability, economics and other topics.