Seems to have all the markings of a California Gull except for the "dark iris". Click each thumbnail for larger photo.

Has the darker gray back, black wingtips, yellowish legs & smaller than a Herring gull (I was able to compare it to a Herring gull that was sitting on a piling ~ 5' away).

Note it has the red & black marks on the bill like a California Gull, different than a Black-tailed gull. The eye is yellow unlike the dark iris of a California gull.