Foto's

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 kmē), mostly in the northwest corner of Wyoming. The park is famous for its various geysers, hot springs, 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.

Long before any recorded human history in Yellowstone, a massive volcanic eruption spewed an immense volume of ash that covered all of the western U.S., much of the Midwest, northern Mexico and some areas of the eastern Pacific Coast. The eruption dwarfed that of Mount St. Helens in 1980 and left a huge caldera 43 miles by 18 miles (70 km by 30 km) sitting over a huge magma chamber (see Geology section and Yellowstone Caldera). Yellowstone has registered three major eruption events in the last 2.2 million years with the last event occurring 640,000 years ago. Its eruptions are the largest known to have occurred on Earth within that timeframe, producing drastic climate change in the aftermath (See also:Supervolcano (documentary)).

The park received its name from its location at the headwaters of the Yellowstone River. French trappers gave this river the name "Roche Jaune," probably a translation of the Hidatsa name "Mi tsi a-da-zi," and the later American trappers rendered the French name into English as "Yellow Stone." Although it is commonly believed that the river was named for the yellow rocks seen in the Grand Canyon of the Yellowstone, the Native American source name more likely derived from the yellowish bluffs located near present-day Billings, Montana.[1]

Info from Wikipedia