DUNCAN, a city of southern Oklahoma, U.S.A., on Federal highway 81 and the Rock Island railroad; the county seat of Stephens county. The population was 3,463 in 1920 (97% native white), and was 8,363 in 193o by the Federal census. The surrounding country is in transition from grazing to intensive agriculture. Dairy and beef cattle, turkeys and pecans are among the specialties. There are oil and gas wells within a few miles. and the city has refineries and casinghead plants and wholesale houses dealing in oil-well supplies, as well as numerous jobbers in other lines. Duncan was settled about 1890 and incorporated in 1899. It has a well equipped airport.