When I lived in the Portland Oregon area lampreys were part of the vocabulary. They migrate up Willamette Falls yearly. The locals harvest them in pretty good numbers. I have fished down river from the falls and the current is crazy. I was told before I went up there that there are nine different currents in that area. I fished it and caught spring chinook while there but never went back. Too many prop busting rocks and crazy current.

Pacific lamprey harvested at Willamette Falls - YouTube