The Edisto River is one of the longest free-flowing blackwater rivers in North America, flowing over 250 meandering miles from its sources in Saluda and Edgefield counties, to its Atlantic Ocean mouth at Edisto Beach, South Carolina. It rises in two main tributaries (North Fork & South Fork) from springs under the Sandhills region of West Central South Carolina, just to the south of the Piedmont Fall Line. It is the longest and largest river system completely contained by the borders of South Carolina. Its name comes from the Edisto subtribe of the Cusabo Indians.