JimShowalter (@JimShowalter)

Tucked in near the banks of the Yellowstone River, Pompey’s Pillar is a rock formation located in Yellowstone County, Montana. A sandstone butte – known for the hundreds of historical markings, pictographs, petroglyphs, and inscriptions – it also bears the signature of Captain William Clark of the Lewis and Clark Expedition. Originally named “Pompeys Tower” in Clark’s original journal entry, Nicolas Biddle altered the name to “Pompey’s Pillar” for the 1814 published history of the expedition. Clark is thought to have named the formation after expedition member Sacagawea’s son, Jean Baptiste Charbonneau, who was nicknamed “Pomp.” Interesting fact: Clark’s inscription is the only known visible evidence of the journey that remains intact. [MHS #PhotoArchives, 950-257, Herman Schnitzmeyer photographer, Between 1922-1929]