Rich,

My hunch is that it's a steelhead. The length suggests that to me, although the length/girth relationship appears near the margin for being either one. Headwater rainbows are usually much smaller, although there are exceptions to most everything. Lower river fish could attain larger sizes, however, they usually get caught and bonked first. And a lower river resident venturing into the headwaters would normally be expected to do so in the spring or summer. It's cool that there are fish out there breaking enough of the rules to keep us confused so that we never completely understand them.

Sincerely,

Salmo g.