The first white explorers discribed the Yellowstone valley as a place of "fire and brimstone" that most people dismissed as delirium. After an 1856 exploration, mountain man Jim Bridger reported seeing boiling springs, spouting water, and a mountain of glass and yellow rock. These reports were largely ignored because Bridger was a known "spinner of yarns".
In 1871 an expedtion finally reached Yellowstone and convinced the US president to protect the wilderness. Yosemite in California had earlier become a state park in .. . But as the Yellowstone area spread not only over Wyoming, but also Montana and Idaho, it became the first national park of the USA.
- Yellowstone National Park(English)
- Birth of a National Park (nps.gov)
- How Yellowstone Became the World's First National Park (time.com)