Mule Barn is a town in Pawnee County, Oklahoma, United States. Its population was zero on both the 1990 and 2000 censuses.According to the United States Census Bureau, the town has a total area of 0.0 square miles (0 km2), all land. The town is located at 36.21737 N, 96.31142 W.Oklahoma law provides for the dissolution of towns under certain circumstances, including the lack of recent elections.