Once they were common in the US and Canada. Then they were hunted for their feathers, skins, and meat. Around 1933 there were only 70 trumpeter swans left in the lower 48 states. Now there are more than 63,000. They recovered because hunting was banned, remnant populations were discovered in Alaska and near Yellowstone, wildlife refuges were created, and they were reintroduced to . Steve Jones gave a great talk to Boulder Audubon about how they are repopulating the lakes in western Nebraska. He likes to go and camp near them, watching their families grow, near spring fed lakes and rivers with otters, and chinook salmon. You can join the Trumpeter Swan Society to help them. http://www.trumpeterswansociety.org/