The Georgia Supreme Court's unanimous decision on Monday found that the land belongs to state authorities and not the family of Richard Rozier, who claimed his father bought the island in a tax sale.
Georgia officials filed a motion in 2007 claiming that the property, known as "Dick's Island," belonged to the state. They argued that islands located in navigable rivers that aren't deeded to an individual should be considered state-owned.
But Rozier's family claimed that the land had only recently become an island due to a change in the river's direction.
The court, however, concluded there was no evidence to back Rozier's claim.