Historically, two Ring-billed Gull (Larus delawarensis) nesting colonies existed in Wyoming (Conover and Conover 1981, Conover 1983). Knight (1902) indicated that this species bred on the Laramie Plains, Albany County. It was also found nesting on the Molly Islands, Yellowstone Lake, Yellowstone National Park (Skinner 1917, Kemsies 1930). I can find no evidence for the four recent Ring-billed Gull nesting colonies Conover (1983) listed for Wyoming.
The intent of this note is to clarify the literature on the recent status and distribution of Ring-billed Gull nesting colonies in the state and provide details on the only known breeding location of this species in Wyoming.