Klamath River · Oregon & California
For a century, four hydroelectric dams held the Klamath still. In 2024 the last of them came out — the largest dam removal ever attempted in the United States. Scroll to descend: from the air above the river, down to the surface, and under it.
Begin the descentFrom above, the shape of the problem is obvious. Four walls, four still pools, and a line the fish could not cross.
RM 224.7 J.C. Boyle
The highest of the four dams sat in a basalt canyon below Upper Klamath Lake, throttling the river into a peaking plant that surged and slackened with demand for electricity. Below it the flow rose and fell twice a day — a river on a timetable.
Fish moving upstream stopped here, and had done so since the concrete cured.
RM 198.6 Copco No. 1
An arch dam poured during the First World War, backing up a shallow reservoir that warmed all summer. Warm, still, nutrient-loaded water is ideal for cyanobacteria, and for decades the blooms behind this wall made stretches of the Klamath unsafe to touch in August.
The reservoir was the problem, not just the wall.
RM 190.1 Iron Gate
Iron Gate evened out the surges from the plants above it, and it became the hard edge of the salmon's world — the furthest upstream a Chinook could reach on the Klamath for more than sixty years. All the cold spring-fed water of the upper basin was simply unavailable.
Its hatchery below the dam existed to compensate for the habitat the dam had closed.
Draining the reservoirs took three weeks. The sediment they had been holding took the rest of the winter to move.
Winter 2024 Drawdown
A century of trapped silt went downstream at once. The Klamath ran the colour of milky tea, dissolved oxygen dropped, and fish in the affected reaches died — an outcome the restoration plan had anticipated and accepted, timed deliberately for winter when the fewest salmon were in the river.
Behind the retreating water, the old valley floors reappeared: stumps cut in 1917, wagon tracks, the meander of the original channel still legible under the mud.
October 2024 Complete
With the last of Iron Gate hauled away, the Klamath ran unobstructed from Upper Klamath Lake to the Pacific for the first time since 1918. Crews moved from demolition to seeding — billions of native seeds spread across the exposed reservoir footprints to hold the sediment before the winter rain.
Roughly 400 miles of historical habitat reopened.
Biologists expected years. It took a season.
Autumn 2024 Return
Within weeks of the last barrier coming out, fall-run Chinook were recorded above the old Iron Gate site — and then further, into Oregon tributaries that had not seen an ocean-going salmon since before the dams. No one guided them. The route had simply become passable again.
What they were looking for is what you are looking at: clean gravel, moving water, somewhere to dig a redd and leave the next run behind them.
The river's recovery will take decades. Its reopening took a season.
The removal was carried out by the Klamath River Renewal Corporation under a settlement two decades in the making, driven above all by the Yurok, Karuk, Hoopa Valley and Klamath Tribes, for whom the salmon runs are not a resource but a relation.
Roughly half a billion dollars, funded by the utility's ratepayers and a California water bond — cheaper, in the end, than retrofitting four ageing dams with fish passage to modern standards.
Sediment will keep sorting itself for years. The measure of success is not the demolition but the count: whether spring-run Chinook, the run that most needed the cold upper basin, re-establishes on its own.