Lake, south-central Missouri, U.S. One of the largest man-made lakes in the U.S., it is located in the scenic Ozark Mountains. It is about 125 mi (200 km) long, with an area of 93 sq mi (242 sq km). It is formed by the Bagnell Dam in the Osage River. The area of Lake of the Ozarks State Park has recreational fishing and water sport facilities and is a popular resort destination. Nearby are several limestone caverns.