Hidatsa Territory About 1800

Before and After 1800

graphic: map of reservation lands around 1800, with label explaining that, at the time of Lewis and Clark's arrival, the Hidatsas' land extended from Mouse River (north) to Heart River (south), Yellowstone River (west) to Turtle River (east).

When Lewis and Clark arrived, the Hidatsa were using a vast area vaguely defined by the Mouse (Souris) River on the north, the Turtle River on the east near today's border with Minnesota, the Heart River on the south, and the Yellowstone River on the west. 'Legal' boundaries were unheard of.