This first-cycle Iceland Gull was digiscoped loafing among Ring-billed Gulls at daybreak 5 December 2010 at "Namacqua Pond" on east side of Namacqua Road in Loveland (Larimer County), Colorado (USA).
Notice the barred tertials, a key field mark that separates juvenal/first basic (i.e. first-cycle) Iceland Gull from pale first-cycle Thayer's Gull.
A very similar bird was spotted by Cole Wild, and seen by several others, in neighboring Weld County (Windsor Reservoir) 2 Dec 2010, perhaps the same individual.