There is still a pretty good "run" of sea lamprey in the Columbia river system. From what I've seen most of them are somewhere around 18-24" as adults - yes they are UGLY. You see one attached to a salmon/steelhead every now and then. You can smack the smallmouth swimming a 6" black curlytail worm on an 1/8 or 1/4 jig head at times, which looks similar to a juvenile lamprey. The sturgeon fisherman below Bonneville Dam use whole adult lamprey - some of those sturgeon down there are over 10 feet long and often come all the way out of the water when hooked. Anyway, that's interesting to see there are "river" lamprey around here, never heard of them...