O·co·nee River (?-k??n?) A river rising in the Blue Ridge Mountains of northern Georgia and flowing about 350 km (220 mi) generally south to join the Ocmulgee River and form the Altamaha River.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.