Iceland Gull (adult, at Thayer's end of spectrum but possibly intergrade with Kumlien's) with Herring and Ring-billed gulls

Size and shape suggest male, with body size in the smaller Herring range, forehead with moderately long slope, and bill size smaller than most Herrings but not petite as seen in many Icelands (Thayer's and Kumlien's), especially females. Primary tone slate gray, mildly lighter than generally seen in Thayer's, suggesting Kumlien's genetic influence. In flight, all primaries above appeared to show long grayish tongues with large white mirror on P10 (at least); below primaries were white with thin dark trailing edge.

"Cook's Inlet" Gull (Glaucous-winged X Herring hybrid) still under consideration but thought less likely due to body and bill size and extensive gray/white on P9-P10.

In this photo notice overall size and bulk, head/bill shape, dark iris, and mostly whitish wingtip below.