This thread is so much fun I took my McPhail-Lindsey off the shelf, blew the dust off, and went through the salmonid key, as it's been a long time.
1. major ray count on anal fin, 12 or less for an Atlantic salmon, 13 or more for chinook. I can't tell from the photo.
2. dark spots on light background, teeth on head and shaft of vomer, forming a strip down the center of the roof of the mouth several times as long as it is wide. Photos don't include a clear shot of vomer.
3. large black spots, many surrounded by pale halos; usually a series of pale or reddish spots along the lateral line. Spots not surrounded by halos, so not a brown trout.
4. no halos, no pale spots along lateral line;
5. red or orange hyoid slashes; usually a few teeth behind the tongue between the gills. No slashes, but can't tell about teeth behind tongue.
6. rod or orange hyoid slash usually absent; never any teeth behind tongue. No slash, but can't tell about teeth behind tongue.
7. teeth on shaft of vomer few, poorly developed, and deciduous, caudal fin usually unspotted, never with regular rows of black spots; adipose fin without a black margin, no lateral red band on spawning adults: can't tell from the photos, but if it meets this criteria it's an Atlantic salmon.
8 - 13 work through the trout and char species.
14. 13 - 19, rarely 12 major rays in anal fin.
15 - 16 work through to ID pink salmon.
17. spots on tail and back small and irregular, the largest much smaller than the vertical eye diameter, posterior adipose eyelid poorly developed, not extending half way to pupil. OK on spots, I think probably on posterior eyelid.
18. flesh along base of teeth in lower jaw black; small black spots on both lobes of tail ---- chinook. To the extent I can see the lower jaw, yes to black flesh along base of teeth. To the extent I can see spots on the tail, yes on small spots, but really I can't see the upper lobe very well.
I still go with chinook. That could change if I could see and count the major anal fin rays and the vomerine teeth.
Sg