Where did Lewis and Clark meet Charbonneau?

While working for the North West Company, Charbonneau encountered the established settlement of Mandan and Hidatsa tribes near present-day Bismarck, North Dakota. He settled amongst these tribes as a trapper, laborer, and an interpreter of the Hidatsa language. When Lewis and Clark wintered there, they met Toussaint and his wife Sacagawea. She was 16 or 17 when she and Toussaint joined the expedition on November 4, 1804.