30557 -- U.S. ZIP code Municipality (1990): MARTIN, Georgia All ZIPs for this municipality (1990): 30557 Population (2000): 4472 Housing Units (2000): 2394 Land area (2000): 57.414620 sq. miles (148.703177 sq. km) Water area (2000): 0.162243 sq. miles (0.420208 sq. km) Total area (2000): 57.576863 sq. miles (149.123385 sq. km) Located within: Georgia (GA) Location: 34.491829 N, 83.175392 W