river in North Carolina and South Carolina, U.S., rising on the eastern slope of the Blue Ridge Mountains and flowing southeast into South Carolina, then south through Sumter National Forest to Columbia, where, after a course of about 220 miles (350 km), it joins the Saluda River to form the Congaree River. The river is dammed for hydroelectric power near the town of Lake Lure, N.C., and at Parr Shoals, S.C.