Pompeys Pillar National Monument
The Pompeys Pillar National Monument is large sandstone rock formation located northeast of Billings, Montana. William Clark, of the Lewis and Clark expedition, etched his signature at the top of the formation. Thus far, the signature is the only known physical evidence of the Lewis and Clark expedition. Clark called the rock formation "Pomp" after the son of Sacagawea, the Shoshoni Native American who accompanied Lewis and Clark on their journey. The word "pompy" means little chief in the Shoshoni language. The rock was given its name Pompeys Pillar in the account of the expedition which was published in 1814. It was designated a National Landmark in 1965, but that designation was removed in 2001 when it was named a National Monument.
Backstory and Context