Effigy Mounds National Monument preserves more than 200 prehistoric mounds built by Native Americans. Numerous effigy mounds are shaped like animals, including bears and birds. These were built mostly in the first millennium, by peoples of the Woodland Culture. In 2010, the United States Mint began issuing 56 quarter-dollar coins featuring designs depicting national parks and other national sites as part of the United States Mint America the Beautiful Quarters Program.