the Ozarks, or Ozark Plateau, upland region, actually a dissected plateau, c.50,000 sq mi (129,500 sq km), chiefly in S Mo. and N Ark., but partly in Oklahoma and Kansas, between the Arkansas and Missouri rivers. The Ozarks, which rise from the surrounding plains, are locally referred to as mountains. Composed of igneous rock overlain by limestone and dolomite, the ancient land form has been worn down by erosion. Summits (knobs) are found wherever there is a resistant rock outcrop; the Boston Mts. are the highest and most rugged section, with several peaks more than 2,000 ft (610 m) high. The Ozarks are rich in lead and zinc, and fruit-growing areas are prevalent. Subsistence farming and household crafts are found in the more isolated regions. The Ozarks have several large lakes that were created by dams across the White and Black rivers; the dams generate electricity. The scenic Ozarks, with forests, streams, and mineral springs, are a popular tourist region, and the construction of summer homes there has grown.