'Specimine of the Stone': The Fate of Lewis and Clark's Mineralogical Specimens by John Jengo
Glacial Drift at Little Sandy, on the Missouri River
Photo by the author
To comply with Thomas Jefferson's instructions to observe the "mineral productions of every kind" as they journeyed across the continent, Lewis and Clark assembled rock and mineral collections on at least three different occasions for shipment back East. As the principal mineralogical collector, Lewis attempted to ensure that the selected specimens were representative of the diverse geology encountered along the expedition route, symbolized here by some of the assorted rocks that comprise the glacial drift at the confluence of Little Sandy Creek and the Missouri River, in Montana.