Okeechobee, Lake (ōˌkēchōˈbē) [key], c.700 sq mi (1,810 sq km), SE Fla., N of the Everglades; third largest freshwater lake and fourth largest lake wholly within the United States. It is c.35 mi (60 km) long and up to 25 mi (40 km) wide, with a maximum depth of 15 ft (4.6 m). The Kissimmee River is its chief source and the Caloosahatchee River its main outlet. In reclaiming the Everglades and adjacent lands, many canals were built extending from the southern part of the lake, itself a link in the Okeechobee Waterway. A levee, built after the disastrous hurricane of 1926, rims the lake's shores, protecting the region from floodwaters and permitting use of the lake as a reservoir. The levees and canals have impeded the flow of water from the lake into the Everglades, which now suffers from saltwater intrusion, and have tended to contain pollutants from agricultural runoff in the lake. The drained lands bordering the lake produce vegetables and sugarcane. Okeechobee Battlefield National Historic Landmark, the site of a large battle (1837) during the Seminole Wars, is nearby.