What caught my eye about this bird was the striking two toned bill. It also seemed to have darker plumage than I am used to seeing around here, especially at the end of its wings.
My inclination is to think this is a California Gull in first winter plumage. However, I am not knowledgable enough to feel this is a definitive identification. It seems like it could also be a young Herring Gull. Any help with this identification question would be appreciated.
It was pointed out to me that the size of the bird relative to other species may be of use in identifying the species, so I have now included a couple of additional photos that show other gulls in the frame. Unfortunately, they are not exactly lined up, so it may be a little difficult to judge relative sizes since they are different distances away.