 "Upland South" is usually defined based on landforms, generally referring to the southern Appalachian Mountains or Appalachia (although not the full region defined by the Appalachian Regional Commission), the Ozarks and Ouachita Mountains, and the plateaus, hills, and basins between the Appalachians and Ozarks, such as the Cumberland Plateau, part of the Allegheny Plateau, the Nashville Basin, the Shawnee Hills, and the Bluegrass Basin, among others.The southern Piedmont region is often considered part of the Upland South, while the Atlantic Coastal Plain (the Chesapeake region and Carolina's Lowcountry) is generally not.In contrast, the term "Upper South" tends to be defined politically by state.