Panther Swamp National Wildlife Refuge is one of seven refuges in the Theodore Roosevelt National Wildlife Refuge Complex in Mississippi. Established in 1978, Panther Swamp National Wildlife Refuge encompasses 38,697 acres (156.60 km²). Included in those acres is one of the largest blocks (21,000 acres) of bottomland forest in the lower Mississippi River alluvial floodplain. The upland areas or ridges often crest at no more than one foot above swamp areas, and contain nuttall, willow and water oaks and other species while overcup oak, bitter pecan and ash dominate the transition zone from swamp to upland.