Grant Area Natural Highlights, Page 2
West Thumb of Yellowstone Lake
Members of the 1870 Washburn party noted that Yellowstone Lake was shaped like "a human hand with the fingers extended and spread apart as much as possible," with the large west bay representing the thumb. In 1878, however, the Hayden Survey used the name "West Arm" for the bay; "West Bay" was also used. Norris' maps of 1880 and 1881 used "West Bay or Thumb." During the 1930s, park personnel attempted to change the name back to "West Arm," but West Thumb remains the accepted name.
West Thumb Geyser Basin
While many of the park's features had been described by mountain men and other explorers, the West Thumb area was the first Yellowstone feature to be written about in a publication. Daniel T. Potts, a trapper in the Yellowstone region in the 1820s, wrote a letter to his brother in Philadelphia, Pennsylvania, regarding his experiences in this area.
The letter was later corrected for punctuation and spelling and printed in the Philadelphia Gazette on September 27, 1827. Part of the letter describing the northern part of the West Thumb Geyser Basin, which is currently known as "Potts Basin" follows:
In 1869, the first scientific expedition to explore the Yellowstone area, the Folsom- Cook-Peterson Expedition, visited the West Thumb Geyser Basin. David Folsom described the area as follows:
Historically, visitors travelling to Yellowstone would arrive at West Thumb via stagecoach from the Old Faithful area. At West Thumb, they had the choice of continuing on the dusty, bumpy stagecoach or boarding the steamship "Zillah" to continue the journey to the Lake Hotel. The boat dock was located near the south end of the basin near Lakeside Spring.
The West Thumb area used to be the site of a large campground, cabins, a photo shop, a cafeteria, and a gas station. This development was located immediately next to the geyser basin with the park road passing between the two. In an effort to further protect the scenic quality and the very resource that visitors were coming to see, the National Park Service removed this development in the 1980s.