Big Lake National Wildlife Refuge is an 11,047-acre (45 km²) National Wildlife Refuge located in Mississippi County, Arkansas, managed by the United States Fish and Wildlife Service. It is situated 2 miles (3.2 km) east of Manila, Arkansas, and consists mostly of a shallow lake, swamp, and bottomland hardwood forests. The preservation of habitat for waterfowl in an intensely agricultural region is the primary purpose of the refuge. 6,400 acres (20 km²) of Big Lake is classified as a National Natural Landmark and 2,144 acres (8 km²) are classified as wilderness.