Yellowstone was established as the first U.S. national park in 1872.
President Ulysses S. Grant signed the Yellowstone National Park Protection Act on March 1, 1872. The law set aside the region as a public park rather than allowing it to be sold or claimed for private development.
Yellowstone lies primarily in Wyoming, with smaller portions in Montana and Idaho. It is known for geothermal features such as Old Faithful, the Grand Prismatic Spring, and the Grand Canyon of the Yellowstone. Native peoples had lived in and used the region for thousands of years before the park was created.
Yellowstone’s creation helped establish the national-park idea in the United States and influenced conservation efforts worldwide. The National Park Service did not yet exist in 1872; it was created in 1916, and the U.S. Army managed Yellowstone for a period before then.