
How did demolishing four aging dams on a river straddling the Oregon and California border, in a project completed in 2024, become the largest dam removal in US history, and what did biologists find swimming upstream within weeks?
Four dams on the Oregon-California border came down in 2024, opening 420 miles of salmon habitat. Within a week of the final blast, sonar arrays detected Chinook moving upstream — and within weeks, they were spawning in Oregon tributaries.














