Yellowstone is the first national park in the United States, established in 1872. Located primarily in Wyoming, it also extends into Montana and Idaho. The park is famous for its geothermal features, including the iconic Old Faithful geyser, and is home to diverse wildlife such as bison, elk, and grizzly bears. Covering over 3,400 square miles, Yellowstone is part of the larger Yellowstone Caldera, one of the largest active volcanic systems in the world. The park offers numerous recreational activities, including hiking, camping, and wildlife viewing, attracting millions of visitors each year.