Washington (where I live) has some good opportunities. Plus, your chance at a true 20lb. fish is better in a certain region of our State.
However, on average, Oregon has more and better opportunities. Due in large part to two circumstances. Hatcheries and gill nets.
First is the political will to allow hatcheries, particularly wild brood stocks programs. Let's just say Oregon has the foresight to support them.
Second is the treaty of 1855 and the Bolt decision with regard to gill nets.
Oregon is not part of this treaty, except for portions of the Columbia. This is not bash or a rant against the tribes. They have a legal right to the practice. If weren't for the tribes, Washington would fewer hatchery fish than they do. Tribal hatcheries produce a significant portion of the state's hatchery fish.
The point is, nets kill fish in the rivers. Even with a 50/50 allocation, a lot more fish were killed, particularly during the 70's 80's and 90's. and the runs never recovered.