Fort Jackson (Colorado)

Fort Jackson was one of the four fur trading forts that lined the South Platte River area north of present-day metro Denver area. It was built by in the early part of 1837 at a cost of $12,000.00 by Peter A. Sarpy and Henry Fraeb and partially financed by the Western Division of the American Fur Company. It was the second or third fort built and was located about one and a half miles south of Fort Vasquez. The location of the fort has not been found as it is on private property and no physical remains survived or have been identified.

This fort was very aggressive and attempted to capture trade in the Rocky Mountains. Sarpy, an aggressive and competitive trader, said that "My object is to do all harm possible to the opposition and yet without harming ourselves." The opposition, Bent, St. Vrain and Co., responded with building their Fort Lookout six miles northwest of present-day Platteville. On December 2, 1837 James C. Robertson went to the Arkansas River area with $937.95 worth of trade goods. The records of this adventure has survived and is available at the Missouri Historical Society in St. Louis. The Cheyenne and the Arapahoes were the aboriginal customers of this fort.

In 1838 inventory of Fort Jackson showed that the fort had domestic animals and the fort had a blacksmith shop at the fort. Trafficking in alcohol was also revealed in this inventory in 1838. In the 1837-38 winter inventor showed a large volume of buffalo robes being taken in and 2,761 were recorded. The value of the robes were listed at $9,319.37. The beaver pelt were valued at $3.37 @ and the Buffalo robes were values at $3.37@. The beaver trade was starting to decline and the Buffalo robes were taking it place with the traders at the fort. With the depression in 1837 of the beaver market, the fort was in decline in this area with the other forts being so close as competitors.

On October 6, 1838 the fort was closed by the American Fur Company and the inventory and stock were removed. The company now sent a wrecking crew from Fort Laramie and the destruction of the fort was complete. The fort that was demolished was set on fire to prevent others from moving in and starting a business in the old remains. According to an alternative explanation of the same events, American Fur Company sold Fort Jackson to Bent, St. Vrain and Co.; the latter abandoned the fort.