La. R.S. 25:766

A historic preservation district commission may be empowered by the local governing body to name or designate any site, location, structure, or monument within the area served by the governmental unit as worthy of preservation whether within or outside of the confines of its historic district and to exercise all other powers and functions of a landmarks commission as specifically enumerated above, except that no historic district commission shall be empowered to act in a landmarks capacity where its jurisdiction overlaps the authority of an existing landmarks commission created pursuant to this Part.