North Carolina stretches across three major physiographic regions of the United States-the Coastal Plain (or tidal region), the Piedmont, and the Appalachians. In addition to creating a spectacular landscape, these regional differences have influenced the state’s climate, soils, plant life, and human geography.
The mountainous region is a plateau divided by two ridges of the southern Appalachian Mountains. To the east are the Blue Ridge Mountains, which rise steeply from the Piedmont to peaks of 3,000 to 4,000 feet (900 to 1,200 meters), and some reach heights of over 6,000 feet (1,800 meters). To the far west, the Unaka Mountains contain the Great Smoky Mountains, which extend west into Tennessee. This region is divided into several transverse ridges and a number of smaller plateaus and depressions. One of the main ranges consists of a group of Black Mountains. About 100 peaks rise to an elevation of 5,000 feet (1,500 meters) in the western part of the state.
North Carolina has about 3,820 square miles (9,890 square kilometers) of inland water, the third largest of any state. Lake Mattamuskeet, covering about 63 square miles (162 square kilometers) in the state’s eastern tidal zone, is the largest natural lake in North Carolina. Lakes are particularly abundant in the Catawba River basin in the southwestern Piedmont and Appalachian states; the river itself is largely a chain of man-made reservoirs. The Catawba is the most populous river basin in the state. The Cape Fear River basin, which occupies much of the southeastern quadrant of North Carolina, is the largest. The Roanoke River drains the northeast corner of the state, flowing southeast from Virginia into the ocean at Albemarle Strait. North Carolina is divided in half from north to south by the Yadkin-Pee Dee River. The Little Tennessee and French Broad Rivers flow northwest from the North Carolina Into Tennessee Mountains. The Raleigh flows with the Neuse River, which flows into the Atlantic Ocean at New Bern.
Soils in North Carolina are generally clustered according to regional characteristics. The coastal soils are rich and humusy, while further west the hills consist mostly of sand and contain almost no organic materials. The Piedmont region is predominantly clayey, and the hill soils are a combination of clay, sand, and silt, commonly referred to as loam. All North Carolina soils are subject to excessive leaching, which causes great loss of minerals, and successful agriculture depends on large additions of fertilizer.