“Snow-whipped peaks of Glacier National Park characterized the wild country [Meriwether] Lewis saw as he explored the Marias River and its tributaries. His route took him within 20 miles [32 kilometers] of the present park boundaries, though no sign of his passing now exists. [William] Clark however, following another route along the Yellowstone River, left a calling card for posterity, carving his name and the date into a sandstone bluff known today as Pompey’s Pillar. Clark named the formation after Sacagawea’s two-year-old son, Pomp, ‘the little dancing boy’ who often rode in Clark’s canoe.”
—From the National Geographic book Lewis & Clark: Voyage of Discovery, 1998