La. Stat. tit. 49 § 4
Current with changes from the 2024 Legislative Session
The water boundary between the States of Louisiana and Mississippi from the mouth of the Pearl river to the Gulf of Mexico is fixed by the decree of the Supreme Court of the United States in the suit of Louisiana versus Mississippi, and marked and buoyed so as to be reasonably permanent and so as to make the location of the line reasonably plain and apparent to those navigating these waters.
La. R.S. § 49:4