State of Texas v. State of Louisiana
This is a formal decree implementing the Supreme Court's earlier 1976 decision in a boundary dispute between Texas and Louisiana, spelling out the precise geographic coordinates of the state line along the Sabine River, through Sabine Lake and Pass, and offshore into the Gulf of Mexico.
The order also resolves ownership of islands in the river and discharges the special master who helped survey and map the boundary, formally closing out this long-running original-jurisdiction lawsuit between the two states.
How it got here: Texas sued Louisiana directly in the Supreme Court's original jurisdiction; after a 1976 ruling on the legal standard, a special master helped survey the exact line for this final decree.
The Case in Depth
What happened
Texas and Louisiana disputed the precise location of their shared boundary along the Sabine River and out into the Gulf of Mexico, including which state (or the United States) owned islands within the river. The Supreme Court, exercising its original jurisdiction over disputes between states, appointed a special master to survey the area and had already issued a decision in 1976 addressing the legal principles governing the boundary.
The question before the Court
Where exactly does the boundary line between Texas and Louisiana run along the Sabine River and out into the Gulf of Mexico?
Why it matters
The decree fixes exactly which state controls specific stretches of land, water, and islands along the Texas-Louisiana border, which matters for taxation, regulatory authority, mineral and oil rights, and law enforcement jurisdiction in the boundary area, including offshore waters relevant to resource extraction.
What changes now
This decree finalizes the boundary determination as a matter of law, so no further merits proceedings are expected. The certified maps must be filed with each state's land office, remaining expense funds are to be returned to the parties, and the special master appointed to survey the boundary is formally discharged, closing out the case.
How the Court got there
The legal reasoning, step by step
- Because the Court had already announced its governing legal ruling on the boundary dispute in June 1976, this later decree exists solely to implement that ruling by fixing precise coordinates and details.
- The Court adopted the specific geographic coordinates surveyed and agreed upon by representatives of both states, using United States Geological Survey quadrangle maps as the technical basis for the line.
- The Court applied the historical rule that territory continuously held since before Texas statehood in 1848, when the western half of the Sabine River was federal territory but not part of Texas, determines present-day ownership of river islands.
- Applying that historical-continuity principle, the Court concluded that neither the United States nor Louisiana holds islands in the west half of the river, and neither the United States nor Texas holds islands in the east half.