Cowan's Fort was built on the land of David Cowan in Castle's Woods. Cowan's property lay near the modern town of Castlewood, on Mill Creek.
Little is known of the construction of Cowan's Fort, other than the fact that it was quite small. Mrs. Scott would later say that her family took shelter in it during Dunmore's War, but that it could house only a few families. Most likely it was a Fort House similar to the surviving Kilgore's Fort House built some 20 years later, rather than a stockade.
It is not known whether Cowan's Fort ever came under direct attack, though there were numerous Indian attacks throughout the Castle's Woods area between 1774 and the mid 1790's. After 1774 when the settlers of Castle's Woods were forced to "fort up", it is likely that they sought shelter at the much larger Moore's Fort a few miles away on Castles Run.