improved portion of the Verdigris and Arkansas rivers, extending southeastward for 439 mi (767 km) from Catoosa (near Tulsa) in northeastern Oklahoma, U.S., through Arkansas to the Mississippi River 25 mi north of Arkansas City, Ark. Approved by the U.S. Congress in 1946 and completed in January 1971, the project controls the Arkansas River's regular flooding and provides a navigable waterway for year-round shipment of the river basin's resources—agricultural products, lumber, petroleum, and coal. Seventeen dams and locks along the waterway, which is 250 ft (75 m) wide and 9 ft deep, create a large supply of hydroelectric power.