Dismal Swamp is one of the largest swamps in the United States. It covers about 750 square miles (1,940 square kilometers) in northeastern North Carolina and southeastern Virginia. Dismal Swamp is a tangle of vines and baldcypress, black tupelo, pine, and white cedar trees. It contains much partly decayed plant life called peat. Its wildlife includes bear, deer, gray fox, opossum, and snakes. Part of the original 2,000 square miles (5,200 square kilometers) of Dismal Swamp was cleared for farming. In 1973, the U.S. Congress established part of the swamp as the Great Dismal Swamp National Wildlife Refuge.