Tuesday July 14, 2026
Active NorCal —
For five hours in 2022, a stretch of the Klamath River held no oxygen at all. Zero. Now scientists know exactly why.
The USGS released a new study documenting how a monsoon storm during the McKinney Fire flushed ash, charcoal, and sediment off scorched hillsides in Siskiyou County and straight into the river. Dissolved oxygen collapsed to nothing and stayed there for more than five hours, suffocating fish along roughly 60 miles of one of the West’s most important salmon rivers.
The research, conducted with the Karuk and Yurok Tribes and two universities, is the first published study to directly link a rain-on-wildfire event to lethal water quality conditions in a large river. Impairments from the 2022 event traveled more than 180 miles downstream.
The fish kill wiped out juvenile salmon, suckerfish, steelhead, and lamprey. For the Karuk and Yurok, who have fought for generations to restore the Klamath’s salmon runs, the loss cut deep.