(ĕt'əwô', ā'tə–) , river, 141 mi (227 km) long, rising in the Blue Ridge Mts., N Ga., and flowing SW to Rome, Ga., where it joins the Oostanaula River to form the Coosa. Allatoona Dam, built for flood control and hydroelectric power, is important in the development and growth of manufacturing in N Georgia and N Alabama. Etowah Mounds, a national historic landmark, is a group of prehistoric Native American earthworks 60 ft (18 m) high, located on the river near Cartersville, Ga.