There are 18 US Post Offices in Rockingham County serving a total of 86,027 residents equating to 4,779 residents per post office. It's estimated that approximately 137,309 packages are handled across the 18 county post offices annually. Rockingham County is a county located in the U.S. state of Virginia. As of the 2010 census, the population was 76,314. Its county seat is Harrisonburg. Rockingham County is included in the Harrisonburg, VA, Metropolitan Statistical Area and is home of the Rockingham County Baseball League."