When was Yellowstone park discovered?

The area was first explored by white men when the Lewis and Clark Expedition passed through part of the area in 1805, after spending the harsher winter months near the present-day town of Great Falls, Montana. Later, John Colter—a member of the expedition who served as a private for Captains William Clark and Meriwether Lewis—described the wonders he had seen in what is now Yellowstone. Although his reports were largely dismissed as fantastic campfire stories for decades after his travels through the area, he is now regarded as the first mountain man (or explorer or trapper) of the region.