Wherever, under the provisions of this Part, a boundary line between two or more parishes is involved, the survey affecting that line shall be approved, in accordance with the provisions of this Part, by the governing authorities of all the parishes affected by the survey before it becomes official and legal.
La. R.S. 50:157
Surveys affecting parish boundary lines; how made official
Official source: Louisiana State Legislature. Reproduced from public-domain Louisiana statutes; confirm against the official source for the current text. Not legal advice.