The Appalachian and Ozark Regions of the United States are quite distinct in their geography, land formations, and culture, from other areas of the country. Several of their subregions will be described, compared and contrasted here.
There are several distinct subregions within the Appalachians and Ozarks, which will be mentioned below.
The Blue Ridge-Great Smoky Mountains section of this region, wherein exists the Blue Ridge Parkway, extends all the way from Georgia in the south to Pennsylvania in the north. This ridge and mountain complex, which extends in the southwest-to-northeast direction, is made of the same type of crystalline-type rock that is found in the Piedmont region just to the east of this ridge and mountain area. As two continental plates pushed against each other, at some time in the past, it caused the continental plate that had the crystalline-type rock to thrust into the upward direction on its western side, over the sedimentary rock found in the continental plate to the west that makes up the rest of the Appalachian country, thus leading to the formation of the Blue Ridge and the Great Smoky Mountains.
Immediately to the west of the Blue Ridge and the Great Smoky Mountains is the Ridge-and-Valley Section of Appalachian country, which is also laid out in the southwest-to-northeast direction. Immediately to the west of the Blue Ridge and Great Smoky Mountains is the Great Valley section of the Ridge-and-Valley Section, which includes the Shenandoah Valley in northern Virginia, the Cumberland Valley in southern Pennsylvania, and the Eastern Tennessee Valley where Knoxville and Chattanooga are. The Great Valley is several miles wide at times, and is bounded by the Blue Ridge or Great Smoky Mountains to the east, and areas of Appalachian ridges to the west, and has some really good agricultural land within its domain.
The series of Appalachian ridges immediately west of the Great Valley section is still collectively known as the Ridge-and-Valley Section of Appalachia, although not part of the Great Valley. Like the Great Valley section, it is comprised mainly of sedimentary rocks that are slightly folded in nature, more so than the Appalachian Plateau to the west of it. Much of it was shaped at some time in the past by erosion patterns, where the harder rock became the ridges, and the softer stone, which eroded away easier, became the valleys. The Ridge-and-Valley Section of Appalachia is also in a southwest-to-northeast direction.
To the west of the Ridge-and-Valley Section of Appalachia, also, like the other sections, laid out in a southwest-to-northeast direction, and also made up of the same type of sedimentary rocks found in the Ridge-and-Valley Section and the Great Valley Section, is what is known as the Appalachian Plateaus, which can be subdivided even further into the Glaciated Allegheny Plateau, the Unglaciated Allegheny Plateau, and the Cumberland Plateau. The eastern boundary of the Appalachian Plateau is known as the Allegheny Front, which is quite steep, and easily defines the boundary between itself and the Ridge-and-Valley Section of Appalachian country. The quality that separates this subregion from the other subregions is the flatness of the sedimentary rocks that underlie this subregion, rather than being slightly folded like the sedimentary rocks in the Ridge-and-Valley Section. Although more flat than this other section, it still has some hilliness to it, due to erosion patterns that happened over time, meaning it is not flat like the Coastal Plains, the Midwestern till country, or the Great Plains.
The Ouachita Mountains and Valleys, which are part of the Ozark region, exist in west-central Arkansas and east-central Oklahoma. This subregion is similar to the Ridge-and-Valley Section of Appalachian country, complete with deep folds and mountain ridges. The only difference that can be seen between this subregion and the similar subregion in Appalachia is the fact that the highest elevation in this area is still about 3800 feet lower than the highest elevation in the Appalachian Mountains.
The Ozark Plateaus, also a part of the Ozark region, are separated from the Ouachita Mountains and Valleys by the broad river valley formed by the Arkansas River. This area covers northern Arkansas and most of the southern half of the state of Missouri. This plateau is only called this because the rock layers that form this area are flat. Even though the layers of underlying rock are flat, erosion, like in the Appalachian Plateaus, has caused the area to have a hilly terrain where, in eons past, drainage of rainwater has formed lots of sloped land. The hilliest parts of this subregion are known as the St. Francois Mountains in southeastern Missouri, surrounding the city of Rolla, and the Boston Mountains in northwestern Arkansas.
One thing that is common within all subregions of both the Appalachians and the Ozarks is the fact that every area, even at the highest elevations, is tree-covered, when not used for agricultural or urban purposes. Both subregions are quite mountainous, have a culture that is more rustic and rural, and are less capable of being used for agricultural or industrial purposes without a great deal of land preparation. Although there are some similarities, there are also some differences, such as in elevation, the direction of the folds in the hill-and-valley sections, as well as the location within the United States, with the Appalachians being farther east, and the Ozarks being farther to the west.
