Contains the journal of expedition member Sergeant Patrick Gass. Gass was promoted to sergeant on the expedition to fill the place of the deceased Charles Floyd. His journal was subsequently published and proved quite popular: it went through six editions in six years. A skilled carpenter, Gass was almost certainly responsible for supervising the building of Forts Mandan and Clatsop; his records of those forts are particularly detailed and useful. Gass was to live until 1870, the last survivor of the expedition and the one who lived to see transcontinental communication fulfill the promise of the expedition.