How was Yellowstone discovered?

Yellowstone was first visited by John Colter, a member of the Lewis and Clark Expedition, in 1807. Colter was part of a small group that spent the winter of 1806-1807 in the Bitterroot Mountains, and during that time he heard stories from Native Americans about a place of great natural beauty and wonder. Colter was the first white man to visit the region of what is now Yellowstone National Park, and his accounts of the geysers and hot springs were met with skepticism by many.

In 1870, a group of explorers led by Nathaniel Langford and James Stevenson was organized to explore the region of the Upper Yellowstone River, and their report confirmed Colter's stories. This led to the establishment of Yellowstone National Park in 1872, making it the first national park in the United States.