These are most likely wild fall chinook heading mainly for the Skykomish and its tribs. Last I heard the Sultan River has a pretty good return of fall chinook. The Snoqualmie system's fall chinook returns are still dismal. It should be fairly obvious to you when you incidentally hook one of these chinook while fishing for pinks or coho. If your fishing light gear it would probably be best to sacrifice your gear and break the fish off rather than killing it by over playing it. None of these chinook are legal to keep or to target for C&R.