The sternwheeler "Chippewa" reaches to within twelve miles of Fort Benton on the Upper Missouri
Charles Chouteau of the American Fur Company took the small stern wheel steamer Chippewa, under Captain La Barge, up the Missouri River as far as the old Fort McKenzie, twelve miles below Fort Benton. This broke all records for navigation on the northern reaches of the river. (By John Osborne)
John Edward Sunder, The Fur Trade on the Upper Missouri, 1840-1865 (Norman, OK: University of Oklahoma Press, 1993), 206.