Spring Chinook salmon (IMAGE) NOAA Fisheries West Coast Region Caption Spring-run Chinook salmon in California’s Central Valley were once the backbone of California’s commercial salmon fishery, but are now a threatened species that remain in a few tributaries of the Sacramento River. Credit Carson Jeffres/UC Davis Usage Restrictions Credit Carson Jeffres/UC Davis License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.