 The expedition started in late May 1859 at St. Louis , Missouri , then was transported by two steamboats up the Missouri River to New Fort Pierre , South Dakota . In late June the expedition left New Fort Pierre and headed overland to Fort Sarpy where they encountered the Crow Indians . Raynolds stated that the Crow were a " small band compared to their neighbors , but are famous warriors , and , according to common report , seldom fail to hold their own with any of the tribes unless greatly outnumbered . " Raynolds was impressed with the Crow chief Red Bear , and after assuring him that the expedition meant only to pass through Crow Indian territory and not linger , traded with the Crows for seven horses . 
