United States v. Louisiana

Background

The dispute involved the federal government and the State of Texas over who owns submerged lands and mineral resources off the Texas coast in the Gulf of Mexico. The Court issued a decree in 1960 and later announced opinions on December 4, 1967 and March 3, 1969; this supplemental decree, entered May 5, 1969, implements those conclusions and describes a detailed boundary line and coordinates.

Reasoning

The core question was where to draw the line between lands belonging to the United States and lands belonging to Texas under the Submerged Lands Act. The Court ordered that the United States holds all lands and resources more than three marine leagues gulfward from the present or future coastline, and that Texas holds lands and resources within three geographical miles and areas landward of the specific line described, subject to exceptions in §5 of the Act. The decree includes precise coordinates, arcs, and straight lines to define the boundary, and it bars Texas and its assigns from interfering with federal rights beyond that line.

Real world impact

The ruling determines who may lease, develop, or control offshore minerals and seabed resources in the specified Gulf areas. The decision provides exact technical measures (distances, grid coordinates, and a North American 1927 datum) for locating the boundary. The decree defines "geographical mile" as 1852 meters and a "marine league" as three geographical miles, and it specifies coordinate systems and datum to guide measurements. The Court retained authority to enforce the decree and issue further orders as needed.

Dissents or concurrances

Two Justices did not take part in the consideration or formulation of this supplemental decree.