The Altamaha River is a major river in the U.S. state of Georgia. It flows generally eastward for 137 miles from its origin at the confluence of the Oconee River and Ocmulgee River towards the Atlantic Ocean, where it empties into the ocean near Brunswick, Georgia. No dams are directly on the Altamaha, though some are on the Oconee and the Ocmulgee. In…The Altamaha River is a major river in the U.S. state of Georgia. It flows generally eastward for 137 miles from its origin at the confluence of the Oconee River and Ocmulgee River towards the Atlantic Ocean, where it empties into the ocean near Brunswick, Georgia. No dams are directly on the Altamaha, though some are on the Oconee and the Ocmulgee. Including its tributaries, the Altamaha River's drainage basin is about 14,000 square miles in size, qualifying it among the larger river basins of the US Atlantic coast.