When I first saw the pic in question, my first reaction was "why are they showing a picture of a steelie?". After thinking about this for a bit, I am reminded of an article that I have from Fishing & Hunting News regarding American Lake. It shows different areas and tactics for a variety of species. But the one that really caught my eye was a tidbit on "Landlocked Steelhead". Now, I am no expert (far cry from an expert, actually), but I was not aware that there was even such a thing as a "landlocked steelie". A rainbow is a trout that stays in the lake. A steelhead is the same fish (dna wise, because steel can have bow offspring and vice versa) that is ocean run. So, by that logic, isn't a "landlocked steelhead" just a rainbow trout?
Anyway, by the looks of the pic, I would have to say that's what I would imagine a "landlocked steelhead" to look like. It does look different than a rainbow in my mind, with the lack of spots and all. So maybe they do exist in American...I just had never seen or heard of one.