Despite what some will say, males will attack with pretty good aggression even if they have been in the river for a bit of time.
I just returned from a trip up in Thunder Bay and witnessed first hand how aggressive chinooks can be on the fly. I have actually not seen them this aggressive before, which maybe attributed to less pressured waters of the north. They went nuts for white zonkers while I was there but I think you will be fine with any variety of streamer patterns like buggers, zonkers, or even classic spey tupe flies.