Fort Sarpy, Montana, was built in 1850 by Alexander Culbertson for the American Fur Company to replace Fort Alexander. It was named for John B. Sarpy, a company partner; however, some preferred to call it by the name of the older post — Fort Alexander, or even combine the names into Fort Alexander-Sarpy. Situated on the north bank of the Yellowstone River, about five miles below the mouth of the Rosebud Creek, it was first operated by Robert Meldrum, an experienced trader who was also an authority on the Crow tribe’s language and customs. Meldrum, who was married to a Crow woman, was known to the Indians as “Round Iron.” Once Meldrum was settled at Fort Sarpy, Culbertson moved on to rebuild Fort Benton in Blackfoot country. The post was approximately 100 feet square and surrounded by 15 foot high pickets. It was abandoned and burned in May 1855. The trading post was sometimes also referred to as Meldrum’s Post. It was located about 15 miles east of Forsyth, Montana.
A second fort called Fort Sarpy was established in 1857. The last post built to trade with the Crow Indians, it was also established by Alexander Culbertson for the American Fur Company. It was located on the Yellowstone River about 25 miles below the mouth of the Big Horn River near present-day Sanders, Montana. The 100-foot-square stockade, surrounded by a palisade of 15-foot-high cottonwood logs, was also referred to as Fort Kipp. It was abandoned in 1860.