Bird Identification: CLOSED: Gull ID, 3 by Elphaba

Elphaba wrote:
Saw this bird as I was leaving. He was pretty far down the beach. I just snapped a few photos and left. Now, I think that maybe I should have paid more attention to it. It was a very big gull but it was all by itself, so I couldn't compare size. I assumed Herring but that big black bill and the black tail makes me think one of the Black-backed gulls? Probably Lesser but I'm hoping for Great.

What do you think?