Waiting for the tide to turn takes patience. My companion on the wait for a high tide last November was this large gull. I thought my patient partner was a herring gull, but I took a closer look and changed my mind.
The subject of my weight(less) contribution has intermediate traits – a dark but not too dark mantle and dark but not black wingtips. My guess is that this is a western gull x glaucous-winged gull hybrid, what birders informally refer to as an Olympic gull. They are common along the coast in the Pacific Northwest, USA.
Here are a couple of informative links on Olympic gulls.