Since the early 90's, I had been seeing Thayer's Gulls at Pickwick Dam in Hardin Co. TN. In '96 there were two Thayer's there at the time of the Ivory Gull sighting and they were confirmed by a few other visiting birders during that period. Pickwick does not lend itself to photographing gulls but finally two birds, a lighter and a darker, stayed and put on a show for quite a few birders. See the Thayer's Gallery for more photos.