The Fifth Principal Meridian, surveyed in 1815, was the first meridian ran for the Louisiana Purchase. The meridian is a north-south line originating from the mouth of the Arkansas River and runs north. The Fifth Principal meridian's principal base line runs west from the mouth of the St. Francis River and forms the initial point at 34°38'44"N 91°3'42"W. These survey lines govern all land surveys in Arkansas, Missouri, Iowa, and North Dakota. In Minnesota, the Fifth principal meridian is used west of the Mississippi River and west of the third guide meridian north of the river. In South Dakota, the Fifth principal meridian survey covers roughly the eastern half of the state.
