My 02 cents!
Rich G's fish
Agree with cohoangler - definitely O. mykiss. Typically adult rainbows in our anadromous streams are 14 to 20 inches with only the very rare fish getting to 24/25 inches. Rich reported the fish as being about 26 inches - too large to be a steelhead jack - most likely a steelhead. With a scale sample could determine for sure whether rainbow or steelhead. A resident rainbow in the 2 foot range would likely be about 10 years old and had spawned 4 or 5 times - a steelhead would be only 4 years old or occasionally a year older if it was a repeat spawner.

The green vegetation in the water would indicate a nearby spring type pond/creek thus some interesting things could be happening though without seeing the spring situation I have no idea what the growth potential might be.

Nailknot's -
Also O mykiss. Pretty much the same comments as above. Though if as I suspect the fish came from the South Fork of the **** in the late fall it would be a 1 salt summer steelhead.

The coloration variations of the old O mykiss complex (even in a small area as Western Washington) can be very interesting and confusing.

Tight lines
Smalma