Mapping the Upper Missouri is a geospatial history of the fur trade, intercultural exchange, and diplomacy in the upper Missouri River region from 1801 to 1853. This project emphasizes sources of visual culture— maps, art, and print— to illustrate differing perceptions and historical experiences in the upper Missouri at its peak of the fur trade. Upper Missouri Indigenous communities were not only participants, but often determined the conduct and expectations of the trade. The growth of U.S. fur companies in the first half of the nineteenth century coincided with a fundamental transformation in the trade’s objectives: from exchange towards ownership of the land. Trading posts ultimately became sites of administration as the U.S. federal government tapped into the system of trust traders had built with Indigenous partners while also recruiting traders as Indian agents. As federal Indian and land policies engulfed the northern plains in a process of national incorporation, Indigenous communities responded strategically in ways that ensured their survival and cultural persistence.