There are 2 US Post Offices in Pierce County serving a total of 4,026 residents equating to 2,013 residents per post office. It's estimated that approximately 6,426 packages are handled across the 2 county post offices annually. Pierce County is a county located in the U.S. state of North Dakota. As of the 2010 census, the population was 4,357. Its county seat is Rugby. The county was created by the 1887 territorial legislature and named for Gilbert Ashville Pierce, governor of Dakota Territory from 1884 to 1886 and a representative of North Dakota in the United States Senate from 1889 to 1891. The county government was first organized on April 6, 1889. The geographical center of North America is in Pierce County, about 6 miles (10 km) west of Balta. Rugby has a monument for the center at the intersection of US 2 and ND 3."