The Tar River and Pamlico River are actually two ecologically distinct pieces of the same river. The 180-mile river rises as a freshwater stream (the Tar) in the Piedmont near Roxboro and changes to brackish water (the Pamlico) as it travels from Washington to the Pamlico Sound. Major tributaries in the upper basin are Swift, Fishing and Tranters creeks and Cokey Swamp. The 30-mile Pungo River is the main tributary in the lower basin.