Jefferson County, New York
Jefferson County is a county on the northern border of the U.S. state of New York. As of the 2020 census, the population was 116,721. Its county seat is Watertown. The county is named after Thomas Jefferson, third President of the United States of America. It is adjacent to Lake Ontario, southeast from the Canada–US border of Ontario.
Jefferson County | |
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County | |
Panoramic view of Boldt Castle on Heart Island | |
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Flag Seal | |
Location within the U.S. state of New York | |
New York's location within the U.S. | |
| Coordinates: 43°59′N 76°03′W | |
| Country | United States |
| State | New York |
| Founded | 1805 |
| Named for | Thomas Jefferson |
| Seat | Watertown |
| Largest town | Le Ray |
| Area | |
| • Total | 1,857 sq mi (4,810 km2) |
| • Land | 1,269 sq mi (3,290 km2) |
| • Water | 589 sq mi (1,530 km2) 32% |
| Population (2020) | |
| • Total | 116,721 |
| • Density | 63/sq mi (24/km2) |
| Time zone | UTC−5 (Eastern) |
| • Summer (DST) | UTC−4 (EDT) |
| Congressional districts | 21st, 24th |
| Website | www |
Jefferson County comprises the Watertown-Fort Drum, NY Metropolitan Statistical Area. The popularity of the area as a summer tourist destination results in a dramatic increase of population during that season.
In 2014, it elected Colleen M. O'Neill as the first woman county sheriff in the state. She had served with the New York State Police for 32 years.
The United States Army's 10th Mountain Division is based at Fort Drum. The base had a total population of nearly 13,000 according to the 2010 census.