“You used to be able to walk across their backs” is the typical refrain, and it makes sense when you watch this footage. The giant mass of salmon — an uncountable number of fish — are stacked up like cordwood in this narrow stream. It’s an amazing sight to behold, and it’s easy to see how millions of people have been enthralled by it. The footage gives us a small glimpse of what the old timers still talk about. Some of the most major rivers on the West Coast used to look like this, but since have seen nearly all of their native salmon and steelhead runs trend downward over the last 50 to 100 years. In some places, wild runs are still hanging on or are supplemented by hatcheries, while in others, the bottom has dropped out entirely. Take the Sacramento, which historically would get 1 million or more fall Chinook in a good year, but now sees runs in the tens of thousands. Or rivers like the Skykomish that flow into the Puget Sound, which used to be salmon superhighways but are now close...