There are 21 US Post Offices in Clinton County serving a total of 79,339 residents equating to 3,778 residents per post office. It's estimated that approximately 126,634 packages are handled across the 21 county post offices annually. Clinton County is a county located in the state of New York, in the United States. As of the 2010 census, the population was 82,128. Its county seat is the city of Plattsburgh. The county is named after George Clinton, the first Governor of New York who went on to become Vice President, having been a Founding Father who represented New York in the Continental Congress. The county lies to the south of the border with the Canadian province of Quebec. Clinton County comprises the Plattsburgh, NY Micropolitan Statistical Area."