In 1795, the place now known as the Yellowstone River first appeared in written records.
In 1797–1798, British explorer and geographer David Thompson, traveling in the Northwest for fur trading, used the word “Yellowstone” in his notes during a visit to a Mandan village in Missouri. Although the towering canyon walls are close to the upper course of the “Yellowstone”, it is uncertain how the name originated.
In 1805–1806, John Colter, a member of the Lewis and Clark expedition, left the expedition and joined a group of trappers in what is now Montana. They heard thunder-like sounds from volcanoes to the south that shook the earth.
In the winter of 1808, John Colter traveled through an area that would later become part of Yellowstone Park. He observed at least one geothermal area near the Tower Falls waterfall in the northeast of Yellowstone. Becoming the first white man known to have explored the area.
In 1827, the first written document about the Yellowstone area appeared in a Philadelphia newspaper, but it seemed to have gone unnoticed, with the focus on its wild history. The earliest known letter about the Yellowstone area was written by trapper Daniel T. Potts, in which he described some of the geothermal features of the area.
In 1829, trapper Joe Meeker stumbled upon the area now known as the Norris Geyser Basin. His description, similar to John Colter’s “fire and brimstone” place, was considered imaginary and fictitious, and was nicknamed “Collter’s Hell”. Over the next forty years, reports from mountain men and fur trappers told of boiling mud, steaming rivers, and petrified trees, but most of these reports were considered myths at the time.
In 1834, Warren Angus Ferris, a salesman for an American fur company, entered what is now Yellowstone Park in order to become famous. He was the first person to actually “tour” the Yellowstone area and the first to provide a full description of the geysers.
Between 1835 and 1839, Osbourne Russell, at the height of the hunter age, ventured into the Yellowstone area three times, reaching many of the hot areas of Yellowstone and Yellowstone Lake to the south.
In 1842, Warren Ferris, a literary messenger from the West, entered Yellowstone. He identified the “geysers” that could retain heat, which was derived from an Icelandic term.
1850-1860, the American Civil War, which was fought over the struggle against slavery, led to the outbreak of the Civil War as a direct consequence. At the same time, small-scale conflicts with Indians continued. The US government decided to explore the Yellowstone area.
After an 1856 expedition, mountain man Jim Bridger, believed to be the first or second European to have seen the Great Salt Lake, also reported seeing boiling springs, geysers, and a mountain made of glass and yellow stone.
In 1859, Captain William Reynolds, a surveyor of the United States Army, began a two-year survey of the Rocky Mountains. After spending a winter in Wyoming, in May 1860, he and a team that included naturalist Ferdinand van der Weer Hayden and guide Jim Bridger set out to cross the Continental Divide at the Wind River Plateau in the northwest of the state. Although hampered by heavy spring snows, they succeeded in their goal, becoming the first organized surveyor to enter the Yellowstone area. However, the outbreak of the Civil War put the expedition on hold until the late 1860s.
In 1863, a group of gold prospectors entered the southern part of Yellowstone. A few years later, the de Lacy Lake area appeared on maps until it was renamed to what is now Shoshone Lake.
In 1865, Francis Xavier Kuppens, a young Jesuit priest, arrived near Great Falls in what is now Montana, where, among other things, he visited the Grand Canyon of Yellowstone and the geysers. Later, Kuppens had the opportunity to describe his incredible journey and suggested to acting territorial governor Thomas Francis Meagher that if such a wonder existed, it should be preserved as a national park.
In 1868, Frederick and Phillip Bottler became the first settlers in Bozeman and the park. The Bottler Ranch was the first base for hunting and prospecting.
In 1869, the Cook-Folsom Peterson Expedition made the first detailed exploration of the Yellowstone area. This expedition was made up of three privately funded explorers. Folsom and his party followed the Yellowstone River to Yellowstone Lake. They recorded the information in a diary and reported it in history, which is known as the Cook-Fulson-Peterson Expedition. Members of Folsom’s team kept an expedition log and reported based on this information.