Art Print: Trumpeter swans, North Americas largest waterfowl. This sanctuary was established in 1935. Near extinction in Yellowstone country in the early 1930s, trumpeters have gradually increased in number. Some 90 pairs nest in Greater Yellowstone each spring. National Geographic photograph by Raymond Gehman, Red Rock Lakes National Wildlife Refuge, Lakeview, Montana. Buy this picture as an unframed print, a framed print, or a mounted box canvas print.