This bird has very white wing tips. There were no gray spots in the primaries though the gray on the outer part of the wing extended fairly far out onto the outer 2 or 3 primaries. The mantle was only slightly paler gray than the mantle color of a Herring Gull.

A rather Thayer's Gull-like Kumlien's Gull (and probably mostly Thayers Gull). The primaries have a noticeable grayish cast, and the mantle was actually a little paler gray than the mantle color of a Herring Gull.

Many of the adult Kumlien's Iceland Gulls we see on Lake Michigan look a lot like this bird, though like snowflakes no two are exactly alike.

This Kumlien's has only a couple gray spots in the primaries. Note the very dark bases to the outer primaries and the dark eye.