Chinook salmon were once abundant in the North Yuba River in California’s Sierra Nevada. But since 1941, they’ve been kept out of the chilly, clear waters by the Englebright Dam. Now, for the first ...

You can do this by building fish ladders. Fish ladders look like a series of small waterfalls alongside a dam. Salmon swim upstream, and they "jump" from one waterfall to the next, until they ...