DescriptionPompeys Pillar National Monument is 1 mi. n. of Pompeys Pillar off I-94 exit 23. William Clark carved his name on this huge sandstone formation in 1806; it is the only physical evidence of the Lewis and Clark expedition through the area. Clark named the rock after guides Charbonneau and Sacagawea's son, Baptiste, whom he nicknamed Pomp. The pillar also bears Native American pictographs and the names of early trappers, soldiers and settlers. Interpretive tours are available upon request at the visitor center.
Daily 8:30-6, early May-Sept. 30. The site is accessible the rest of the year only by a half-mile walk from a parking area. Admission $7 (per private vehicle). Phone (406) 875-2400 for the visitor center, or (406) 896-5013 for the Bureau of Land Management.