Yellowstone National Park is located primarily in Wyoming and is home to the Yellowstone supervolcano. The supervolcano has erupted massive explosions over 2.1 million years ago and could potentially wipe out 2/3 of the United States if it were to erupt again. Yellowstone is also famous for its geothermal features like geysers, containing the majority of the world's most famous geysers, including Old Faithful. Yellowstone was established as the first national park in the United States in 1872 and sees over 3 million visitors each year who come to experience the natural beauty and geology of the park.