Fort Bennett was established on May 17, 1870 by Captain Edward P. Pearson, 17th U.S. Infantry, as a one company U.S. Army post to protect the Cheyenne Agency Indians. It was originally known as The Cheyenne Agency Post. The fort had three palisaded sides and one open side facing the Missouri River. Following the Custer Massacre in 1876, the fort hosted up to nine companies of troops. It was re-named on Dec. 30, 1878, after Captain Andrew S. Bennett, 5th U.S. Infantry, who was killed 4 Sep 1878 by hostile Bannock Indians at Clark's Fort, Montana. It was abandoned Nov. 18, 1891. (Source: fortwiki.com)
Fort Bennett was located on the West side of the Missouri River just south of the mouth of the Cheyenne River. There was a post office, several residential buildings, a blacksmith shop, hospital, and barracks for both enlisted men and officers. There were also Cheyenne Agency offices and a warehouse that stored supplies and provisions intended for Agency residents.
Some of the fort's buildings were intact until the 1960s. Some buildings were moved to higher ground, including the old officers' quarters. Employees of the Diamond A ranch working cattle in the area occasionally used the building as an overnight shelter. Some regretted the choice and tell stories of ghostly figures, noises coming from various unoccupied parts of the building, and even a pipe that was mysteriously lit and left burning on a shelf.
Remains of the Fort could be seen until completion of the Oahe Dam in the early 1960s. Most of the fort is now under Lake Oahe.
