Fort Fetterman

Fort Fetterman was constructed in 1867 by the United States Army on the Great Plains frontier in Dakota Territory, approximately 11 miles northwest of present-day Douglas, Wyoming. Located high on the bluffs south of the North Platte River, it served as a major base for the start of several United States military expeditions against warring Native American tribes. The fort is listed on the National Register of Historic Places.

Source: Wikipedia