East Tennessee comprises approximately the eastern third of the U.S. state of Tennessee, one of the three Grand Divisions of Tennessee defined in state law. East Tennessee consists of 33 counties, 30 located within the Eastern Time Zone and three counties in the Central Time Zone, namely Bledsoe, Cumberland, and Marion. East Tennessee is entirely located within the Appalachian Mountains, although the landforms range from densely forested 6,000-foot (1,800 m) mountains to broad river valleys. The region contains the major cities of Knoxville and Chattanooga, Tennessee's third and fourth largest cities, respectively.