Crab Orchard National Wildlife Refuge in southern Illinois spans 43,890 acres around Crab Orchard Lake, with forests, wetlands, brushland, fields, grazing areas, and additional lakes including Devil's Kitchen Lake and Little Grassy Lake. It is a major migratory bird stop along the Mississippi Flyway and an important wintering area where Canada geese can number about 200,000. The refuge supports extensive biodiversity, including nearly 1,000 vascular plant species and hundreds of animal species. It is notable for combining conservation, recreation, agriculture, and industry, including land and buildings that trace back to World War II explosives production and remain in industrial use today.