There are 10 US Post Offices in Rockbridge County serving a total of 28,325 residents equating to 2,833 residents per post office. It's estimated that approximately 45,210 packages are handled across the 10 county post offices annually. Rockbridge County is a county located in the Commonwealth of Virginia. As of the 2010 census, the population was 22,307. Its county seat is Lexington. The independent cities of Buena Vista (6,680) and Lexington (7,170) are both enclaved within the county's geographical borders.