It's a steelhead. I didn't read all the replies so not sure everything that's been said, but, tounge color can vary a bit. Was the toungue black or dark or grayish? (apparently it was not white) What about teeth on or under the tounge? Any? Big? Small? The Anal fin on this steelhead appears more square (as it should) in the top pic than the bottom, the steelhead also appears still alive in the top pic, recently dead in the bottom pic. (look at the eye) I suspect the dude hiding behind the kid in the second pic wacked the fish in between the first and second pics. And the fish ripped its anal fin in the ensuing small thrashing. The angle also in the second pic is deceiving cuz it makes the nose appear more stubby than it really is, look close up in the first pic with the mouth more close together. Not nearly as stubby as the second pic looks. But I've caught salt steelhead that look a lot like that. It is so fresh it looks like one from the salt. And who says a steelhead can't have a slightly goofy anal fin? We see goofy stuff on fish all the time. The leading edge of the anal fin on the fish pictured appears to be awfully light colored, steelhead have a dull whitish leading edge of the anal fin when fresh, and then it starts to pink out after being in the river awhile. Steelhead in the salt do lose scales like coho. (not quite as bad) Look at a close up of some of the scale loss toward the shoulders of the fish, where there is scale loss you can see some awfully small scattered spots, not kinger spots.
OOps, well, save the pic to your computer, then zoom in on areas of the fish yourself.
The tail in the first pic does appear to be square with faintly visible spots towards the top, not much visible towards the bottom, and the color of the tail appear too light to be a kinger. The bottom pic, the kid just has the tail folded in on itself a bit to give it the appearance needed to trick ya all.
If you look at the fish as a whole, there is more that makes it look like a steelhead than anything else. If you pick it apart, there is a couple things that leave it up for opinion. But, a coho that bright would have much more scale loss based on the apparent handling of the fish, look at all the fish slime/wetness on the kids shirt and wader and the dude standing next to him in the first pic. Also, the faint purple hue is from the goofy setting I'll bet they have their camera on based on the bluish color in the rest of the pic. Teh belly is just so white, the shape so torpedoish, the head so hen steelheady, and the frickin time of year say a very nice steelhead with a couple slightly goofy faults developed just to drive Todd and some other experts insane trying to figure out what kind of fish this is. This fish was made to give something to do, like debate forever on it's identity, for fish crazed people, especially single bachelors when the rivers are all blown.
Of course I could definately be completely wrong. Wouldn't be the first time, but I still think it's a steelhead. A springer this early I don't think would have such a plump full roundish belly.