Yellowstone National Park is a U.S. National Park located in the states of Wyoming, Montana, and Idaho. Yellowstone is the first and oldest national park in the world and covers 3,470 square miles (8,980 km²), mostly in the northwest corner of Wyoming. The park is famous for its various geysers, hot springs, supervolcano and other geothermal features and is home to grizzly bears, wolves, and free-ranging herds of bison and elk. It is the core of the Greater Yellowstone Ecosystem, one of the largest intact temperate zone ecosystems remaining on the planet. The world's most famous geyser, the Old Faithful Geyser, is also located in Yellowstone National Park.-------------- The American Bison (Bison bison) is a bovine mammal that is the largest terrestrial mammal in North America, and one of the largest wild cattle in the world. With their huge bulk, wood bison – which are the largest subspecies in North America – are only surpassed in size by the massive Asian gaur and wild water buffalo, both of which are found mainly in India. The bison inhabited the Great Plains of the United States and Canada in massive herds, ranging from the Great Slave Lake in Canada's far north to Mexico in the south, and from eastern Oregon almost to the Atlantic Ocean, taking its subspecies into account. Its two subspecies are the Plains Bison (Bison bison bison), distinguished by its smaller size and more rounded hump, and the Wood Bison (Bison bison athabascae), distinguished by its larger size and taller square hump. ------------------------------------- The Bison is also commonly known as the American Buffalo, although it is only distantly related to either the Water Buffalo or African Buffalo.