Corrected ID; Lesser Black-backed Gull (thanks to Amar Ayyash  www.anythinglarus.com)
Fisherman Point, Stanley County, SD
May 21, 2016

This gull had me confused at first sighting. From a distance, I could see the gray back and tail band, the bill was obviously large, but the bill and the gull didn't appear to be as large as it turned out to be. I thought maybe it was a Laughing Gull. Then it flew to where I could get a better look, this was a good lesson in not trying to judge size when there are no other gulls or anything else to compare it to.

Quote from Amar Ayyash: "This is a 2nd summer LBBG that has just recently begun its 3rd prebasic molt (note the new, 3rd generation inner primaries just beginning to emerge)."