NA-120 Louisiana State West (Cameron to St Mary Parish) group

Marsh Island is an uninhabited low-lying marshy island in Iberia Parish, south coastal Louisiana, lying between Vermilion Bay and the Gulf of Mexico. It is bordered on the south by the Gulf of Mexico and is separated from mainland Louisiana by East Cote Blanche Bay to its east, West Cote Blanche Bay to its north, Vermilion Bay to its northwest, and Southwest Pass to its west