Missouri River near Fort Mandan - ND. On April 7, 1805, the party of 33 men, Sacagawea and her infant son, and Lewis' Newfoundland dog left their winter quarters with six dugout canoes and two pirogues loaded to their limits. Corporal Warfington and the return party of 12 men set off in the keelboat for St. Louis with materials for President Jefferson.
