31324 -- U.S. ZIP code Municipality (1990): RICHMOND HILL, Georgia All ZIPs for this municipality (1990): 31324 Population (2000): 14508 Housing Units (2000): 5262 Land area (2000): 130.303703 sq. miles (337.485026 sq. km) Water area (2000): 0.154335 sq. miles (0.399726 sq. km) Total area (2000): 130.458038 sq. miles (337.884752 sq. km) Located within: Georgia (GA) Location: 31.906365 N, 81.310806 W