Thought to be a GWGU, but suspiciously looks like a SBGU with it's large bulky size, hefty bill, sloped forehead, lightish eye, and the face looks very slaty-like with a deep pink orbital eye ring. The back is too light though, and so are the wingtips, so maybe not a SBGU? perhaps a hybrid between a Glaucous-winged? Its hard to tell in the photos what the accurate mantle shade is due to the lighting unfortunately.https://flickr.com/photos/pampered_oaks/47990992602/in/photolist-fCr8A8-qjxUg1-2g7NECv-2g7NEfS-2g7Noyy-2g7NDeU-2g7NDaL-2g7No7W-2g4JkbT-XqR1jq-XqR1hG-XqQZZ7-XqQZQu-XqQZNq

FIRST PHOTO:
Olympic Gull (GWGUxWEGU) - top left
Gull hybrid (GWGUx?) - mid left
Iceland gull (kumlieni) - right, facing left
Glaucous-winged Gull - right, facing right
probable sbgu x gwgu?

More photos here: https://www.inaturalist.org/observations/34102481