The Tundra Swan breeds on the high tundra across the top of North America. It is a migratory bird coming through Montana in the late fall and winter. There is some evidence of this species overwintering in the vicinities of Glacier Park, west central Montana (i.e. near Stevensville and the Lee Metcalf National Wildlife Refuge) and Yellowstone Park. Tundra Swans are similar in appearance to Trumpeter Swans but the latter is larger. Trumpeter Swans rarely show any yellow on the lores, while Tundra Swans have very evident yellow lores (evident in many of these photos).