Rockingham -- U.S. County in New Hampshire Population (2000): 277359 Housing Units (2000): 113023 Land area (2000): 694.964635 sq. miles (1799.950065 sq. km) Water area (2000): 99.000155 sq. miles (256.409214 sq. km) Total area (2000): 793.964790 sq. miles (2056.359279 sq. km) Located within: New Hampshire (NH), FIPS 33 Location: 42.962870 N, 71.077622 W Headwords: Rockingham Rockingham, NH Rockingham County Rockingham County, NH