EXTRA: Watch the dam demolition.
Before we fully understood anadromous fish, the kind that swim upstream to spawn, we put a lot of obstacles between them and their spawning grounds.
Dams big and small went up on creeks and rivers, preventing fish passage.
Now many dams are coming down, including one on Cottonwood Creek in Tehama County.
U.S. Fish and Wildlife oversaw the project, which returns five miles of stream to spawning habitat.