South Carolina is roughly a triangle covering 30,989 square miles, 494 of which consist of water area. From the northwest corner a jagged man-made line, running east and southeast for 333 miles to Little River Inlet, marks the boundary between the two Carolinas; the Savannah River, with its tributaries, the Tugaloo and the Chattooga, extending southeast from the same corner for 238 miles to Tybee Sound, separates, the State from Georgia; while the Atlantic shore line stretches for approximately 190 miles, between Little River Inlet and Tybee Sound.
The Blue Ridge Mountains occupy an area of about 500 square miles in the northwestern part of the State. The highest point, Sassafras Mountain (alt., 3,548 ft.), is almost on the North Carolina boundary. The South Carolina mountains are not spectacular, but their broken outline, soft blue color, and sunny exposure give them peculiar charm. Outcroppings of granite are not uncommon, and at Table Rock and Caesar's Head are vertical cliffs of gneiss. From this mountainous border the land drops successively to the Piedmont Plateau, the Sand Hills, the Coastal Plain, and sea level, over a distance of about 235 miles. The mean altitude of the State in general is estimated at 350 feet.
The chief physical feature of South Carolina, though not the most picturesque, is the fall line, which roughly bisects the State along a diagonal between the North Carolina boundary in Chesterfield County and the Georgia boundary in Aiken County. It separates two regions commonly known as the Up Country and the Low Country--regions differing in custom, history, and livelihood. The main part of the Up Country is composed of the Piedmont Plateau, with its rolling hills, ragged woods, small farms, and newly developed industries. The soil of this region is red clay, originally covered with a thin but rich layer of forest-formed humus. Much of this top soil has been washed away, and the roads, cutting through clay banks, look as if carved from scarlet cheese. These clay lands will produce good crops of corn, cotton, and vegetables if the missing humus is supplied and conserved.
In the level Low Country lie alluvial regions and much swampland where, since the State's beginning, large plantations have depended chiefly on a single crop--first indigo, then rice, and later cotton. Tobacco has recently become of considerable importance in the Low Country, as well as truck or vegetable crops. The Sand Hills along the fall line constitute the least productive agricultural land in the State, although recently peaches and grapes have been found well adapted to this intermediate region.
South Carolina is drained by three main river systems: the Pee Dee in the northeast, the Santee in the central area, and the Savannah in the southwest. Tributaries of the Pee Dee are the Little Pee Dee, the Waccamaw, and Lynches; the Santee is formed by the confluence of the Wateree and the Congaree (the latter made up of the Broad and the Saluda); and the Savannah in its upper reaches is joined by the Tugaloo, the Chattooga, and the Seneca. The Edisto River in the southeast is independent of the three main systems. The swift flow of the streams in the Up Country has led most of the State's manufacturing plants to select sites in that section. Below the fall line, these red, mud-laden rivers become wide and comparatively clear, depositing their silt on the bottom. Stained black with tannic acid from cypress and other roots, they run slowly through flat rich soils to the Atlantic Ocean. Between Georgetown and the Savannah River, along more than two thirds of the coast line, is a border of sandy barrier islands; while north of Georgetown an arc of unbroken beach extends to the North Carolina boundary. There are no large inland lakes in the State, except those formed artificially by river dams.
In climate, South Carolina ranges from temperate in the northwest to semitropical in the southeast. The lowest annual mean temperature for any station in the State is that of Caesar's Head in Greenville County, 54.9°; the highest is that of Beaufort, being 67.3°. The State as a whole has an annual mean temperature of about 63°, with normal seasonal variations. Summers are long and hot, but not as en ervating as is generally supposed. Nights are cool in the Up Country, and the heat is tempered by sea breezes near the coast. April, May, and October are the pleasantest months in the Up Country, and the winter season is mild and pleasant below the fall line. Rainfall is abundant and evenly distributed throughout the year. Growing seasons range from 186 days in the mountains to 284 days along the coast.