Established in 1872 and located primarily in Wyoming, Yellowstone National Park was America's first national park. To this day, Yellowstone remains one of the country's most popular national parks with millions of annual visitors.

The world's first national park is Yellowstone National Park, which is primarily located in the northwest corner of Wyoming, although its vast boundaries also extend into parts of Montana and Idaho. Established on March 1, 1872, when President Ulysses S. Grant signed the Yellowstone National Park Protection Act into law, it set a global precedent for land conservation. Spanning nearly 3,500 square miles, the park sits atop a volcanic hot spot, resulting in the world's largest concentration of geothermal features, including the iconic Old Faithful geyser and the vibrant Grand Prismatic Spring. Beyond its hydrothermal wonders, Yellowstone serves as a critical sanctuary for diverse wildlife, including grizzly bears, wolves, and the largest free-roaming herd of bison in the United States. In 2026, it remains a "crown jewel" of the National Park Service, drawing millions of visitors who come to witness the raw, primordial beauty of the American West. The park's creation was a revolutionary idea that suggested certain natural wonders are so significant they should belong to everyone rather than being exploited for private gain.