Salmon surge after Klamath dam removal

• The study, the first to quantify salmon returns after the dams were removed, was published in the journal Scientific Reports.

Catch up quick: After decades of advocacy, the last of the hydroelectric dams on the Klamath was taken out in the summer of 2024, returning the river to a free-flowing state it hadn't seen in more than a century.

What they did: Researchers used sonar, video monitoring and surveys of live fish and carcasses to count how many Chinook salmon returned to their breeding grounds on the upper part of the river and its tributaries.

By the numbers: They counted nearly 7,500 returning Chinook in 2024.

• In 2025, that number jumped by roughly 72% to more than 13,000 fish.
• Chinook recolonized nearly 90% of their historical habitat just two years after access was restored.

Researchers also documented the return of coho salmon, steelhead and Pacific lamprey to the upper Klamath.

What they're saying: "I don't think any of us, in our wildest dreams, expected this many fish this quickly to repatriate that area," Keith Parker, a fisheries biologist with the Yurok Tribe who argued for removal for decades, told the New York Times.

Yes, but: The numbers may have been bolstered by good ocean conditions, said Scott Hinch, an ecologist at the University of British Columbia.

• "It's been quite remarkable, the speed at which this has happened," Hinch, who was not affiliated with the study, told the Times. "We have to be careful not to gauge our expectations too high, as oceans continue to warm."

The bottom line: The long-term success of salmon on the Klamath will take years to gauge, but the early returns have exceeded expectations.