That a 30-year-old mining engineer wrote the first accurate account of Yellowstone’s geography may not seem like a big deal. But had David E. Folsom and his friends Charles Cook and William Peterson not crossed through the Montana territory into present-day Yellowstone in September 1869, the country’s largest national park might not exist.
According to the Atlanta Journal-Constitution, Folsom's 1869 handwritten manuscript begins: "The headwaters of the Yellowstone, although occasionally visited by small parties of prospectors and mountain men, and being within a few days ride of Virginia City, is still to the world of letters a terra incognita."
Folsom’s account also includes the trio’s adventures fishing in Yellowstone Lake, measuring the height of Yellowstone Falls and exploring the geyser basin.
When the three friends penned their descriptions of the bubbling geysers and huge waterfalls, many publishers refused to print it, saying that the discoveries seemed too incredible to be true. But the editors at a small Chicago monthly were intrigued, and in June 1870, the Western Monthly published their story.
And the country took note.
Two government expeditions, the Washburn-Doane-Langford expedition of 1870 and the Hayden scientific expedition in 1871 set out because of Folsom’s account, and soon after, in 1872, Congress deemed the Yellowstone area the world’s first national park.
Although two original versions of Folsom’s Western Monthly article burned, the last remaining copy is housed in a fireproof vault in the archives of the Montana State University library.