Watertown is a city in the State of New York and the county seat of Jefferson County. It is situated approximately 20 miles south of the Thousand Islands. As of the 2010 census, it had a population of 27,023, an increase of 1.2% since 2000. The U.S. Army post Fort Drum is near the city. Geographically, Watertown is located in the central part of Jefferson County. It lies 72 miles (116 km) northeast of Syracuse, New York and 31 miles (50 km) south of the Ontario border. The city is served by Watertown International Airport.