There are 15 US Post Offices in Horry County serving a total of 266,610 residents equating to 17,774 residents per post office. It's estimated that approximately 425,539 packages are handled across the 15 county post offices annually. Horry County (/\u02c8\u0252ri\u02d0/ ORR-ee) is a county in the U.S. state of South Carolina. As of the 2010 census, its population was 289,650, making it the fifth-most populous county in South Carolina. The county seat is Conway. Horry County is included in the Myrtle Beach-Conway-North Myrtle Beach, SC-NC Metropolitan Statistical Area. It is located in the Pee Dee region of South Carolina, approximately 90 miles north of Charleston, South Carolina and approximately 130 miles east of the state capital, Columbia."