2025 Map of Western Isles Dernieres

About this map

Isles Dernieres and the fragile barrier complex of Raccoon Island define this maritime landscape along the Louisiana coast. This 2025 survey by the U.S. Geological Survey captures the shifting morphology of the southernmost reaches of Terrebonne Parish. The map documents the western terminus of the island chain at Raccoon Point, where the land meets the vast expanse of the Gulf of America. To the north, the waters of Caillou Bay are separated from the open sea by these narrow landforms, which are bisected by tidal passes like Coupe Colin. The stark nature of the map, dominated by open water and wetlands, underscores the vulnerability and dynamic character of these coastal features. For those studying Louisiana's changing shoreline, this record provides a precise look at the footprint of these barrier islands in the mid-2020s.