Pompeys Pillar National Monument is a remarkable testament to human history, showcasing hundreds of markings, petroglyphs, and inscriptions that create a living journal of the American West. For over 11,000 years, many peoples celebrated this sandstone outcrop as a landmark and outstanding observation point, with explorer William Clark of the Lewis and Clark Expedition leaving his mark alongside countless others.
Visit the Monument and climb the boardwalk to the top of the pillar, learn about the Lewis and Clark expedition and more at the Visitor Center, and enjoy the picturesque riverside grounds and trails.
Hours and Seasons
For the 2026 season, we will open on 01 May 2026 and close on 01 October 2026 (so, our last day of operation for the 2026 season will be 30 September 2026).
The Monument is closed every Tuesday for maintenance. Monument gates open each day at 8:00am, and close at 4:00pm. The Monument and the adjoining Area of Critical Environmental Concern are open during daylight hours only. When the vehicle gates are closed, including on Tuesdays for maintenance, visitors are welcome to park outside the gates and walk-in (during daylight hours only).
Camp Observer
