In 1966 the State of Ohio filed suit in the U.S. Supreme Court against the Commonwealth of Kentucky. At issue was the location of the boundary between Ohio and Kentucky. The State of Ohio claimed that the boundary was the low-water mark on the northerly side of the Ohio River as it existed in 1792, when Kentucky was admitted to the Union. The banks along the Ohio River have changed and expanded due to human influences and activities, such as dredging and damming of the river for navigation. The Commonwealth of Kentucky filed a counter suit that the boundary is the current location of the northern boundary of the Ohio River.
On January 21, 1980, the Supreme Court of the United States ruled in Ohio’s favor when it decided that the boundary is the low-water mark on the northerly side of the Ohio River as it existed in 1792 (OHIO v. KENTUCKY, 444 U.S. 335 ). The original U.S. Supreme Court decision can be accessed at Openjurist.org.
Following the decision, a Report of the Special Master was filed with the Supreme Court on April 15, 1985 (OHIO v. KENTUCKY, 471 US 153 ), and contained the legal determination of the Ohio-Kentucky boundary. Joint Exhibit No. 5 of the report contained the U.S. Geological Survey 7.5-minute topographic maps, which showed the boundary, while Joint Exhibit No. 30 of the report is the table of geodetic coordinates of the Ohio-Kentucky boundary. The Supreme Court decision on the Report of the Special Master can be accessed at Openjurist.org.
Ohio-Kentucky Boundary Geodetic Coordinates
Geodetic coordinates can be downloaded by clicking one of the links below. The original table of Joint Exhibit No. 30 has been scanned into PDF format. Coordinates have been captured into a Microsoft Excel spreadsheet, a text document, and converted to GIS shape file. Coordinate information was digitized from original USGS documents and data files created by Kentucky Environmental and Public Protection Cabinet, Geographic Information Systems Branch, and Commonwealth Office of Technology, Division of Geographic Information.
Ohio-Kentucky Boundary Maps
U.S. Geological Survey planimetric 7.5-minute quadrangle maps have been published showing the redefined boundary and are listed below. Each map is $5.00.