Which U.S. national park was established in 1872 after a major expedition explored its wonders?

Yellowstone National Park was established in 1872 after a major expedition explored its wonders.

The Yellowstone area became nationally famous through the 1871 Hayden Geological Survey, led by Ferdinand V. Hayden. Survey members documented geysers, hot springs, waterfalls, and the Grand Canyon of the Yellowstone, while photographer William Henry Jackson and artist Thomas Moran helped bring the scenery to a wider public.

President Ulysses S. Grant signed the Yellowstone National Park Protection Act on March 1, 1872. The law set aside more than two million acres as a public park and prohibited private settlement, sale, or occupation of the land. Yellowstone is widely regarded as the world’s first national park.

The park lies mainly in northwestern Wyoming, with smaller sections in Montana and Idaho. It is especially known for Old Faithful, although Old Faithful is a geyser rather than the park itself. Yellowstone also contains one of the world’s largest active volcanic systems.