There are 17 US Post Offices in Putnam County serving a total of 84,083 residents equating to 4,946 residents per post office. It's estimated that approximately 134,206 packages are handled across the 17 county post offices annually. Putnam County is a county located in the state of Florida. As of the 2010 census, the population was 74,364. Its county seat is Palatka. Putnam County comprises the Palatka, FL Micropolitan Statistical Area, which is included in the Jacksonville-St. Marys-Palatka, FL-GA Combined Statistical Area. The county is centrally located between Jacksonville, Gainesville, St. Augustine, and Daytona Beach."