I hate to sow seeds of doubt, but I've caught some resident bows on S-rivers that look remarkably similar to that, if a little smaller. Could be a small post-spawn 1-salt winter run buck, though that's sounds about as rare as they come... Noticeable snout, blotchy cheeks, muted stripe, darker belly, and darker fins have me thinking it's not a summer run. I don't want to be a Debbie Downer. It's just that the fish is an interesting one for this time of year. Steelhead or not, that fish is a beautiful rarity.