I remember when we were kids, Dad would fish for them off the beach in the Columbia- off of Hayden Island.
We've caught them recently in the Cowlitz- 2-3 years ago there were more to be caught. Last year only got a couple. Yes, they are cuttthroat. I think WDFW stopped stocking them (or greatly reduced the numbers)in the Cowlitz like they used to because they think they may be reducing salmon runs.
We caught them near the Vader/ I-5 bridge or near Castle Rock.
My friends fish for them just west of Longview from the bank on the Columbia.
Jim