> checking out Salmon swimming through locks out of season

To be fair, the Coho salmon run at the Ballard locks peaks in September. It's possible you just had bad luck that day.

https://ballardlocks.org/fish-salmon-ladder.html

I run by the locks a few times a week and while I don't usually see fish, the presence of sea lions the last few weeks tells me that at least some salmon are running right now.