There are 8 US Post Offices in Montgomery County serving a total of 177,495 residents equating to 22,187 residents per post office. It's estimated that approximately 283,302 packages are handled across the 8 county post offices annually. Montgomery County is a county located in the U.S. state of Virginia. As of the 2010 census, the population was 94,392. Its county seat is Christiansburg. Montgomery County is part of the Blacksburg\u2013Christiansburg\u2013Radford, VA Metropolitan Statistical Area.