Altamaha, a river of Georgia., about 140 m. long, which is formed by the confluence of the Oconee and the Ocmulgee, in the S. E. central part of the state. Its course is S. E. through sandy plains and pine barrens to the Atlantic, about 12 m. below Darien, and about 60 m. S. W. of Savannah. For vessels of 30 tons it is navigable through its entire extent.