2020 Map of Western Isles Dernieres

About this map

Isles Dernieres forms a narrow, shifting barrier chain between the Caillou Bay and the open Gulf of Mexico along the Louisiana coast. This 2020 survey of Terrebonne Parish highlights the precarious nature of these landforms, showing the western extremity of the archipelago including Raccoon Island and its westernmost tip at Raccoon Point. The mapping captures the coastal geomorphology of the region, where the shallow waters of Coupe Colin separate the fragmented land masses. These islands serve as critical buffers for the mainland, and their documented footprint here provides a baseline for understanding the rapid environmental changes and erosion patterns affecting the Gulf coast. The map is defined by vast aquatic expanses, with only the thin ribbon of the islands and the established Public Land Survey System boundaries, such as those for T24S R15E, providing terrestrial reference points.