Yellowstone National Park, established by the U.S. Congress in 1872k is the first national park in the United States and the world. It spans almost 3,500 miles, extending into parts of Montana and Idaho, and is renowned for its geothermal features, wildlife, canyons, lakes, mountains, rivers, and waterfalls. The park sits on top of a dormant volcano and contains about half the world’s active geysers, including the famous Old Faithful. Yellowstone encompasses more than 2.2 million acres, most of it beyond the reach of roads. One could dedicate their entire life to experiencing the park and still never see it all.

Britannica