Nestled on the banks of the Yellowstone River, Pompeys Pillar National Monument rises 120 feet into the sky. This sandstone outcropping, covering roughly 2 acres at its base, is not just a geologic wonder but a site of cultural and historic significance. Although perhaps best known for the inscription left behind by William Clark of the Lewis and Clark expedition, this site boasts the markings of thousands of years of human occupation.
We invite you to take a journey through our website to explore and learn more about the history of Pompeys Pillar National Monument.
We are a 501 (c) (3) non-profit organization established in 1989 to support Pompeys Pillar National Monument, which contains the last remaining inscription of the Lewis and Clark Expedition of 1803-1806. Our mission is to preserve and protect the Monument by educating visitors through interpretation, special projects, and by supporting the Bureau of Land Management (BLM) in its management of the site. The effort of the Pompeys Pillar Historical Association was a driving force to get this site into the public lands domain, which resulted in the purchase of the historical land from the Foote family by the BLM in 1991. By working cooperatively with the BLM in the planning and administration of the site, the Pompeys Pillar Historical Association successfully accomplishes this mission.
We look forward to your visit!
July 6- August 6: Reimagining America: The Maps of Lewis and Clark, a traveling exhibit from the Lewis and Clark Trail Heritage Foundation
July 25: Signature Day • Free admission
July 30: Star Party
Walk-ins after hours are always welcome. Approximately a one mile walk from gate to Pillar.
May – September
October (Weather Dependent)
Front Gates: 8:00am – 4:00pm
RV parking spots are available.
3039 Highway 312 Pompeys Pillar, MT
The Pillar overlooks the Yellowstone River about 25 miles east of Billings, Montana. The area is easily accessible from I-94, using exit 23.
Only during operational months and hours.
Pompeys Pillar National Monument accepts and sells the following Interagency passes: