These are the ten longest rivers that flow through the state of New York. The criteria for ranking on this list is the total length of a river, not just the length of the river flowing in New York State. I've also listed approximations of how many miles each river flows in New York.
The ten longest rivers located in the state of New York. That is the ten longest rivers that flow through New York. Half of these rivers flow entirely through New York, while the other five flow through multiple states.
I'm familiar with most of these rivers, as I was born in New York State. I live in New Jersey, about equal distance from two rivers on this list, the Delaware and the Hudson. A relative of mine lived most of her life on the banks of one of these rivers.
10 Longest Rivers in New York
1. Saint Lawrence River- 744 miles
The Saint Lawrence River flows 744 miles from Lake Ontario to the Gulf of Saint Lawrence where it empties into the Atlantic Ocean. The Saint Lawrence makes up the border between New York State and Ontario, Canada, for roughly 100 miles between Lake Ontario and Cornwell, New York.
2. Susquehanna River- 464 miles
The Susquehanna River flows 464 miles from Lake Otsego in Cooperstown, New York, to where it empties into the Atlantic Ocean in the Chesapeake Bay. The Susquehanna River flows roughly 150 miles through New York State before it crosses into Pennsylvania southwest of Binghamton.
3. Allegheny River- 325 miles
The Allegheny River flows 325 miles from its source on Cobb Hill in Potter County, Pennsylvania, to where it merges with the Ohio River at Pittsburgh, Pennsylvania. After rising on Cobb Hill some 10 miles south of the New York border, the Allegheny River works its way north into New York State where it flows for maybe 35 miles before it re-enters Pennsylvania.
4. Hudson River- 315 miles
The Hudson River flows 315 miles from its source at Lake Tear of the the Clouds on Mount Marcy in the Adirondack Mountains to where it flows into the Atlantic Ocean through the Narrows in New York Bay in New York City. The Hudson River is the longest river that flows entirely through New York State, though it does make up the border with New Jersey for 25 miles near its end by New York City.
5. Delaware River- 301 miles
Both the East and West Branches of the Delaware River start in New York State. The West Branch begins on Mount Jefferson in Schoharie County, and the East Branch begins in the town of Roxbury in Delaware County.
The branches meet near the New York and Pennsylvania border just north of Hancock, and then the Delaware River forms the border between the two states for roughly 80 miles, before the Delaware trades New York for New Jersey at Port Jervis. In total, the Delware River flows 301 miles from New York State to where it empties into the Atlantic Ocean at Delaware Bay.
6. Genesee River- 157 miles
The Genesee River begins in Ulysses Township in northwestern Pennsylvania near the New York border a few miles south of Genesee, Pennsylvania. The Genesee River then flows north 157 miles to where it drains into Lake Ontario at Rochester, New York. The Genesee River carved out what is known as the Grand Canyon of the East in Letchworth State Park on its way to Lake Ontario.
7. Mohawk River- 149 miles
The Mohawk River flows 149 miles entirely through New York State from its source in southern Lewis County to where it drains into the Hudson River just north of Albany.
8. Raquette River- 146 miles
Image Source by Jondude11
Raquette River runs 146 miles entirely in New York State from its source at Raquette Lake to where it flows into the Saint Lawrence River. The Raquette River is often a fast flowing river that has over two dozen hydroelectric plants located along it.
9. Oswegatchie River- 137 miles
The Oswegatchie River runs 137 miles entirely through New York from its sources in the Adirondack Mountains to where it flows into the Saint Lawrence River. There are a few waterfalls along the Oswegatchie River, including the High Falls of the Oswegatchie River pictured above.
10. Black River- 125 miles
The Black River flows 125 miles entirely through New York from its sources in the foothills of the Adirondack Mountains to where it flows into the Saint Lawrence River. My aunt lived along the Black River for most of her life and we used to fish in the river as kids whenever we visited her. The Black River is a large river and also has waterfalls along it including the Great Falls pictured above.
For more see 10 Longest Rivers in the United States
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10 Tallest Buildings in New York
Tallest Churches in New York