Caddo Lake National Wildlife Refuge is an 8,493-acre protected area near Karnack, Texas, on the edge of one of East Texas's most important wetland landscapes. In the 19th century, its loamy soils supported cotton plantations, and during World War II the site became the Longhorn Army Ammunition Plant, linking it to the region's wartime industry. Its present role grew from the ecological importance of the surrounding wetlands, which were recognized in 1993 at the Ramsar Convention as internationally significant. Authorized in 2000, the refuge protects the bottomlands of Harrison Bayou and habitat for migratory birds.