This bird was part of the group of gulls frequenting the town pier in Plymouth, MA (behind the East Bay Grill). Most Iceland Gulls found in the US are of the Kumlien's type and they can be virtually impossible to tell apart in field in some situations. This one, however, has been determined to be a Kumlien's after looking at the primary feathers clearly shown in this photo. I've been told that "Iceland (nominate) has to have snow white primaries without ANY trace of gray, and even then may not be identifiable."