Oneida Lake is the largest lake entirely within New York State

New York

New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

 (79.8 square miles (206.7 km²)). The lake is located northeast of Syracuse

Syracuse, New York

Syracuse is a city in and the county seat of Onondaga County, New York, United States, the largest U.S. city with the name "Syracuse", and the fifth most populous city in the state. At the 2010 census, the city population was 145,170, and its metropolitan area had a population of 742,603...

 and near the Great Lakes

Great Lakes

The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...

. It serves as one of the links in the Erie Canal

Erie Canal

The Erie Canal is a waterway in New York that runs about from Albany, New York, on the Hudson River to Buffalo, New York, at Lake Erie, completing a navigable water route from the Atlantic Ocean to the Great Lakes. The canal contains 36 locks and encompasses a total elevation differential of...

. It empties into the Oneida River

Oneida River

The Oneida River in central New York state flows from Oneida Lake to its confluence with the Seneca and Oswego rivers. The Oswego empties the water of the other two rivers into Lake Ontario....

 which flows into the Oswego River

Oswego River (New York)

The Oswego River is a river in upstate New York in the United States. This river is the second-largest river flowing into Lake Ontario. James Fenimore Cooper’s novel The Pathfinder, or The Inland Sea is set in the Oswego River valley...

 which in turn flows into Lake Ontario

Lake Ontario

Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north and southwest by the Canadian province of Ontario, and on the south by the American state of New York. Ontario, Canada's most populous province, was named for the lake. In the Wyandot language, ontarío means...

. While not included as one of the Finger Lakes

Finger Lakes

The Finger Lakes are a pattern of lakes in the west-central section of Upstate New York in the United States. They are a popular tourist destination. The lakes are long and thin , each oriented roughly on a north-south axis. The two longest, Cayuga Lake and Seneca Lake, are among the deepest in...

, it is sometimes referred to as their "thumb".

The lake is about 21 miles (33 km) long and about 5 miles (8.7 km) wide with an average depth of 22 feet (6.4 m).