The Tulsa District was established in 1939 and is one of four districts that make up the Southwestern Division. Its civil works boundaries include Oklahoma and parts of southern Kansas and northern Texas. The district's Civil Works mission is one of the largest in the Corps of Engineers; it includes 38 multipurpose lakes and five lock and dams on the McClellan-Kerr Arkansas River Navigation System. Although the primary purpose of district lakes is flood control, they also provide recreation, water supply, hydropower, navigation, and fish and wildlife habitat. The district's 150 miles of the MKARNS boasts the most inland, ice-free river port in America and provides waterway commerce to the heartland of the country. District projects have prevented billions of dollars in flood damages and the district's eight hydropower facilities provide about $52 million in annual sales. The district has 240 parks with more campsites -- 6,000-- than any other district in the Corps. The Tulsa District's military construction mission provides engineering and construction management services to two Army and four Air Force installations. During the last 10 years, the district has managed the design and construction of more than $1 billion in facilities for its military customers.