Columbia Fur Company

The company was bought by John Jacob Astor in 1827, and reorganized as the Upper Missouri Outfit of the Western Department of the American Fur Company, withdrawing its operations on the Great Lakes and leaving it to the Northern Department of the American Fur Company. Pierre Chouteau Jr. became the chief executive of the Western Department, while Kenneth McKenzie became manager of the Upper Missouri Outfit, operating above the mouth of the Big Sioux River. McKenzie built Fort Union at the mouth of the Yellowstone River as the Outfit's center of operations.^[1][5][6]

• Fort Floyd 1826 ^[7]
• Fort Lookout 1822, near Fort Kiowa.^[8][9]
• Fort Tecumseh 1822 ^[10]
• Ponca Post, near Nanza just below the mouth of the Niobrara River.^[11]
• Tilton's Post or Tilton's Fort, built in 1822 on the opposite site of the Missouri from the Mandan villages. In 1823 the post was moved to the villages, to get protection from Arikara attacks.^[12][13]
• Post at the mouth of White Earth River, 1825-1831. Replaced by Fort Clark.^[12]

When Columbia Fur Company sold out to Astor in 1827, the following posts were included in the deal:^[14]

• Council Bluff
• Vermillion
• Rivière à Jacques
• Ponca Post
• Fort Tecumseh
• Mandan Villages

• Barbour, Barton H. (2001). Fort Union and the upper Missouri fur trade . Norman: University of Oklahoma Press.
• Chittenden, Hiram Martin (1902). The American Fur Trade of the Far West. New York: Francis P. Harper.
• Jones, Evans (1966). Citadel in the Wilderness. Minneapolis: University of Minnesota Press.
• Robertson, Roland G. (1999). Competitive Struggle: America's Western Fur Trading Posts, 1764-1865. Caldwell, Idaho: Caxton Press.
• Wishart, David J. (1979). The Fur Trade of the American West 1807-1840. University of Nebraska Press.