Winter at Fort Mandan - Fort Mandan Park, ND. On October 26, 1804, the Corps arrived at the Mandan-Hidatsa villages and later built a fort across the Missouri. There they spent the winter writing in their journals and preparing items to send to President Jefferson. A French trapper, Toussaint Charbonneau and his wife, Sacagawea, arrived in November and offered their services as guides and interpreters.
