The American Bison, or Buffalo, is the largest terrestrial mammal in North America, and once inhabited the Great Plains in massive herds. They were central to the lives of Native American tribes.
This pile of bison skulls from the 1870s illustrates the extent of their slaughter in the 19th century by white settlers: from a population of about 60 million in 1800 to as few as 750 in 1890. They have since been reintroduced into the wild and are no longer considered a high risk endangered species.