The easternmost section, about 10 miles (16 km) in width, consists of hilly land that runs along the western bank of the Tennessee River. To the west of this narrow strip of land is a wide area of rolling hills and streams that stretches all the way to the Mississippi River; this area is called the Tennessee Bottoms or bottom land. In Memphis, the Tennessee Bottoms end in steep bluffs overlooking the river. To the west of the Tennessee Bottoms is the Mississippi Alluvial Plain, less than 300 feet (90 m) above sea level. This area of lowlands, flood plains, and swamp land is sometimes referred to as the Delta region. Memphis is the economic center of West Tennessee and the largest city in the state.