This California river once carried thousands of salmon every year. A 1942 dam changed it forever, and scientists are still trying to bring them back

Friant Dam construction in 1942 on the San Joaquin River reduced river flows and eliminated spring-run Chinook salmon from the upper river.

A 1988 lawsuit by the Natural Resources Defense Council argued that dam operations violated California's requirement to maintain enough water for fish below dams.

A 2006 settlement agreement established the San Joaquin River Restoration Program to restore salmon while balancing water for agriculture.

The program involves multiple agencies conducting scientific research and habitat improvements to reestablish spring-run Chinook salmon.