In August 2024, the Klamath River in Northern California flowed freely for the first time in over a century. The world’s largest dam removal project—demolishing four hydroelectric dams—marked a turning point for river restoration in the United States, reopening hundreds of miles of habitat and offering a rare glimpse of rapid ecological recovery.
Century-Old Dams Come Down
The J.C. Boyle, Copco No. 1, Copco No. 2, and Iron Gate dams, constructed between 1918 and 1962, once generated 163 megawatts of electricity for the region. Yet their legacy was one of environmental decline. The dams blocked salmon and other migratory fish from reaching spawning grounds, causing Chinook salmon populations to plummet by 90 percent and spring Chinook by 98 percent. Iron Gate, the tallest at 173 feet, was the last to fall, ending a chapter of ecological disruption that had persisted for generations.
The $450 million project, funded by PacifiCorp and the state of California, was driven by the realization that removing the aging dams was less costly than upgrading them to meet modern environmental standards. The removal process began in earnest in late 2023, with Copco No. 2 coming down first. By August 2024, all four dams were gone, and contractors had carefully managed the release of five million cubic yards of sediment, using bypass tunnels to control water flow and minimize downstream impacts.
Tribal Leadership and a Turning Point
The campaign to remove the dams was led by the Yurok, Karuk, Klamath, and other Basin tribes, for whom salmon are central to culture, ceremony, and sustenance. For decades, tribal leaders and advocates pressed for restoration, often facing skepticism and legal hurdles. Their persistence paid off, culminating in a project that many once considered impossible.
A pivotal moment came in September 2002, when more than 60,000 adult salmon died in the Klamath River below the dams due to low water flows and poor conditions. The disaster galvanized public support, uniting tribes, environmental groups, and government agencies in a shared mission to restore the river.
Salmon Surge and Habitat Revival
The ecological response was swift and dramatic. Within a week of the final dam’s removal, fish were detected passing the former Iron Gate site. Two weeks later, Chinook salmon reached spawning grounds in Oregon that had been inaccessible for over a century. By the end of 2024, nearly 7,700 fish had passed through the former dam site, with Chinook making up the vast majority.
In October 2024, fall Chinook salmon were observed in tributaries above the former J.C. Boyle Dam, and video footage captured salmon ascending Keno Dam and entering Klamath Lake for the first time since 1912. By mid-October 2025, the Shasta River counted 5,745 adult Chinook—triple the number from the previous year. The rapid rebound exceeded scientists’ expectations and underscored the resilience of native fish populations when barriers are removed.
Restoring Water Quality and Ecosystem Health
The dam removals reconnected 420 miles of river habitat, allowing salmon to access cold-water tributaries vital for spawning and juvenile survival. The river’s transformation extended beyond fish: stagnant reservoirs that once fostered toxic blue-green algae blooms gave way to naturally aerated, cooler waters. Tribal monitoring stations documented steady improvements in dissolved oxygen and turbidity, while temperature regulation reduced disease outbreaks among aquatic species.
Managing the release of sediment was a key challenge. The short-term influx of silt temporarily muddied the water, but scientists anticipated this impact and pointed to similar projects, such as the Elwha River in Washington, where water quality rebounded within two years.
A Massive Effort to Replant and Rewild
Restoration extended to the land as well. Teams began planting up to 19 billion native seeds across 2,200 acres of former reservoir beds, representing 96 species of trees, shrubs, and wildflowers. Yurok crews had spent years collecting seeds and partnering with nurseries to ensure a diverse and resilient plant community. The revegetation strategy included “facilitation patches” to help native plants outcompete invasive species, and by 2025, wildflowers and young pines were already taking root.
Wildlife responded rapidly. Bald eagles, otters, beavers, and ospreys returned in greater numbers, and researchers documented a surge in biodiversity throughout the watershed. The ecosystem, long suppressed by the dams, began to rebound almost immediately.
Looking Ahead: A Model for Restoration
For the Yurok and other tribes, the return of salmon is more than an environmental victory—it is a cultural rebirth. The hope is that future generations will once again celebrate salmon festivals with fish from their own river, not distant imports.
Federal investments, including $18 million from NOAA for post-dam restoration, support ongoing monitoring and habitat improvements. Scientists use sonar, radio tagging, and in-river sampling to track recovery, though recent funding cuts threaten long-term research.
The Klamath project stands as a precedent for river restoration nationwide, demonstrating that ecological recovery can happen faster than expected. As the United States invests in further dam removals, the lessons from the Klamath offer hope for rivers and communities across the country.