Pompeys Pillar National Monument MT (#0471)

This worked out to be one of the best experiences of my trip. Pompeys Pillar National Monument, in the town of the same name, preserves the only actual mark of Lewis and Clark's expedition (see later pictures). The monument is run by the BLM and has a very good exhibition about Lewis and Clark's expedition and the native populations. Being a relatively unknown monument, it was lightly visited and easily explored. See:
www.blm.gov/programs/national-conservation-lands/montana-dakotas/pompeys-pillar