Pompeys Pillar National Monument

Pompeys Pillar National Monument encompasses 51 acres on the banks of the Yellowstone River with a massive sandstone outcrop covering about 2 acres at its base and rising 120 feet high toward Montana’s Big Sky. The Monument’s premier location at a natural ford in the Yellowstone River, and its geologic distinction as the only major sandstone formation in the area, have made Pompeys Pillar a celebrated landmark and outstanding observation point for more than 11,000 years of human occupation. Hundreds of markings, petroglyphs, and inscriptions left by visitors including William Clark and the Lewis and Clark Expedition have transformed this geologic phenomenon into a living journal of the American West. 

The BLM-managed public land adjacent to the Monument is designated as the Pompeys Pillar Area of Critical Environmental Concern (ACEC), which is approximately 432 acres. The ACEC was designated to protect the significant cultural resources along with riparian ecosystem and fish and wildlife habitat. The ACEC is open to walk-in access year-round.

Hours

Main Gate (May 1st – Sept. 30th): 8:30 a.m. – 4:30 p.m.

Interpretive Center (May 1st – Sept. 30th): 9 a.m. – 4 a.m. 

NOTE: Even when the Monument is closed, visitors may still walk into the site during daylight hours. The walk from the gates to the Pillar is about 3/4 of a mile. Special arrangements can be made during the off-season for school programs and other special events.

Available Facilities

  • Amphitheater
  • Interpretive Center
  • Day Use Areas include boardwalks & Walkways
  • Vault Toilets
  • Picnic Tables

The interpretive center, restrooms, parking lot and day-use area are fully accessible.

Educational Programming 

Opportunities may exist to schedule field trips to the site. For more information please email blm_mt_ppnm_pillarschoolgroups@blm.gov

Pets

Pets must be on a leash at all times. Please pick up after your pets. Dog waste stations are present throughout the Monument. 

Be Respectful!

Please respect the heritage of Pompeys Pillar National Monument. Do not deface any tree, shrub, rock, or ancient Indian artifact. Do not touch petroglyphs or remove any artifact. Not only is this illegal, but it also erases evidence of past generations and deprives others of knowledge about these sites.