What is the yellow stone national park?

Yellowstone National Park is an American national park located in the western United States, mainly in the state of Wyoming, although it also extends into Montana and Idaho. It was established by Congress and signed into law by President Ulysses S. Grant on March 1, 1872. Yellowstone was the first national park in the United States and is also widely held to be the first national park in the world. The park is about 3,472 square miles (8,983 km2), comprising lakes, canyons, rivers and mountains. Yellowstone Park is known for its wildlife and its many geysers, including Old Faithful Geyser, as well as hot springs and mud pots. The park is managed by the National Park Service and has an estimated 4 million visitors each year.