The Nels Severson Barn, also known as "Fort" Severson, is a historic barn located north of Carpenter in rural Mitchell County, Iowa, United States. It is a two-story structure composed of irregularly-cut limestone with a gable roof. Its walls are 18 inches (46 cm) thick. It is one of a few, and possibly the only, stone structure in the area.[2] The barn was built by Norwegian immigrant Nels Severson in 1867. He and his brother Ole were early settlers in this region. Local tradition refers to the building as a fort. Its large size and sturdy construction would protect the white settlers from Indian attacks. It is also said that it was a stop on a stage coach line. While the latter might be true, there is no evidence to corroborate either tradition.[2] The barn was listed on the National Register of Historic Places in 1977.
