There are 58 US Post Offices in Ulster County serving a total of 225,944 residents equating to 3,896 residents per post office. It's estimated that approximately 360,632 packages are handled across the 58 county post offices annually. Ulster County is a county located in the U.S. state of New York. As of the 2010 census, the population was 182,493. The county seat is Kingston. The county is named for the Irish province of Ulster. Ulster County comprises the Kingston, NY Metropolitan Statistical Area, which is also included in the New York-Newark, NY-NJ-CT-PA Combined Statistical Area. It is located in the state's Mid-Hudson Region of the Hudson Valley"