31038 -- U.S. ZIP code Municipality (1990): ROUND OAK, Georgia All ZIPs for this municipality (1990): 31038 Population (2000): 752 Housing Units (2000): 330 Land area (2000): 103.108301 sq. miles (267.049262 sq. km) Water area (2000): 0.204653 sq. miles (0.530049 sq. km) Total area (2000): 103.312954 sq. miles (267.579311 sq. km) Located within: Georgia (GA) Location: 33.172786 N, 83.635546 W