References:
- https://en.wikipedia.org/wiki/Yellowstone_National_Park
- https://www.britannica.com/place/Yellowstone-National-Park
- https://www.factretriever.com/yellowstone-facts
- https://www.nationalgeographic.com/news/2015/12/151204-yellowstone-facts-national-parks-history/
- https://www.history.com/news/10-things-you-may-not-know-about-yellowstone-national-park