The park is located in the U.S. state of Wyoming but also extends into Montana and Idaho. It is not only the first national park of the U.S.A. but is also thought to be the first in the world. It is known for its wildlife, geothermal features such as the Old Faithful Geyser and ecosystems such as those in the subalpine forest. Yellowstone National Park spans an area of 3,468.4 square miles and contains canyons, mountain ranges, rivers and lakes as well as the largest super volcano on the continent. It has always been a popular tourist resort, especially for Americans.