There are 3 US Post Offices in Boyd County serving a total of 31,723 residents equating to 10,574 residents per post office. It's estimated that approximately 50,633 packages are handled across the 3 county post offices annually. Boyd County is a county located in the U.S. state of Kentucky. As of the 2010 census, the population was 49,542. The county seat is Catlettsburg, and its largest city is Ashland. The county was formed in 1860. Its 160 square miles (410 km2) are found at the northeastern edge of the state near the Ohio River and Big Sandy River, nestled in the verdant rolling hills of Appalachia. Boyd County is part of the Huntington-Ashland, WV-KY-OH Metropolitan Statistical Area (MSA). As of the 2010 census, the MSA had a population of 287,702. New definitions from February 28, 2013 placed the population at 363,000."