United States v. LOUISIANA

Background

The dispute involves the State of Mississippi, the United States, and the State of Alabama over coastal seabed boundaries. In a prior 1985 decision the Court found Mississippi Sound to be a historic bay and treated its waters as inland, with Alabama and Mississippi owning their respective seabed portions. The Special Master filed a supplemental report on March 16, 1987, noting agreement on Alabama’s coastline but a two-point disagreement between Mississippi and the United States about Mississippi’s seaward boundary and proposing competing decrees. Mississippi also sought to expand the dispute southward toward Chandeleur Sound, an area previously affected by a separate Louisiana boundary decree.

Reasoning

The central question was whether the current phase should resolve Mississippi’s claims south of Mississippi Sound. The Court held that this phase concerned only Mississippi Sound and that it would not decide Mississippi’s rights south of that Sound without full agreement and the Special Master’s willing consideration. Mississippi’s exceptions to the Special Master’s report, which did not challenge the Sound’s closing lines, were overruled without prejudice to raise those southern claims in a separate proceeding. The Court adopted the Special Master’s recommendations to the extent consistent with this opinion, directed the parties to submit a proposed decree defining Mississippi Sound, split the Special Master’s expenses between the United States and Mississippi, and retained jurisdiction.

Real world impact

The ruling clarifies and implements the boundary and ownership of Mississippi Sound but leaves about 150 square miles near Chandeleur Sound undecided. Mississippi and the United States may file new complaints over Chandeleur Sound within 60 days, with 45 days for any response, so further litigation may follow.