Ohio v. Kentucky

Background

The States of Ohio and Kentucky fought over where their border runs along the Ohio River. Ohio filed suit in 1966 asking the Court to say the line is the low-water mark on the river’s north bank as it was in 1792; Kentucky argued the border is the current low-water mark. A Special Master heard the case, recommended the 1792 line, and the parties filed exceptions and replies before the Court.

Reasoning

The Court focused on whether the border should be the 1792 low-water mark or the river’s present low-water mark. It relied on historical documents about Virginia’s cession and on earlier decisions, concluding that Kentucky succeeded to the river and that the boundary is fixed at the northerly low-water mark as it existed in 1792. The Court adopted the Special Master’s recommendation, overruled Kentucky’s exceptions, and directed further work to set the exact line.

Real world impact

The ruling means officials must locate a shoreline position from 1792, a task the Court said surveyors can perform but that may be difficult. The decision affects who controls land, enforces laws, and collects taxes along the river. The case was returned to the Special Master to prepare a formal decree and, if needed, to conduct further hearings and surveys.

Dissents or concurrances

Justice Powell (joined by Justices White and Rehnquist) dissented, arguing the border should move with changes in the river under common-law riparian rules and warning that fixing the 1792 line creates uncertain, hard-to-identify boundaries.