As the resident guy who targets almost exclusively invasiv species, let me just say I hope northern pike never make it to OR! Don't get me wrong...I DIG pike on the fly, but they would massacre the native species. They are just way too efficient a predator and trout, as well as the steelhead and salmon smolt would just get crushed. The smallmouth bass are a tough enough gauntlet for the smolt. I do dig em though...love to fish for them when I am in the Midwest and caught a beast in Alaska one year.
I think there are some lakes in WA that hold them...but I don't believe OR had any like waters...I hope it states that way. I heard they are entering the Columbia system up in Eastern WA...not good.