Pompey's Pillar

The panel credits Clark with naming the rock for Sacagawea's son, but the name he wrote was another. His journal for July 25, 1806 calls it Pompy's Tower, after the boy he nicknamed Pomp, and notes two piles of stone the Indians had raised on its top. The 1814 published history of the expedition renamed it Pompey's Pillar. Clark's carved name and date, now under shatterproof glass in a bronze frame, are the only physical evidence of the journey known to remain. The rock became a national monument on January 17, 2001.

Where it stands

Worth the stop nearby

• Pictograph Cave State Park — 27 mi
  Three sandstone shelters outside Billings whose 1937 dig gave the northern plains its timeline, and whose paintings are fading.

More markers nearby

• Camp #44 of the 1873 Yellowstone Expedition — steps away
• Buffalo Country — 14 mi
• Junction of Bighorn and Yellowstone Rivers — 15 mi
• Junction of Bighorn and Yellowstone Rivers — 18 mi