They are a native species to the PNW and their scientific name: Ptychocheilus oregonensis
Note the Oregon in the name
In my opinion, the bounty on them on the Columbia is a bit of a smokescreen to detract attention from the habitat loss created by the dams themselves. Perhaps the dams have created a competitive advantage for them and thinning them there makes some sense, but certainly elsewhere they are just a part of the balance of nature. I always release them.