The bison is a majestic, massive creature, a true emblem of the American frontier spirit. These sturdy animals roamed North America"s prairies for thousands of years in numbers estimated to be as high as 60 million. But settlement of the American West caused habitat loss, and that, combined with overhunting, nearly wiped out the species altogether by the end of the 19th century. Ranchers, conservationists, Native American tribes, and politicians teamed up to save the bison and today, nearly 500,000 bison can be found in North America. About 15,000 animals are in free-roaming herds that graze on US public lands, like the bison in today"s image, shown at Grand Teton National Park in Wyoming.