The Longest Rivers in North America

The Missouri River as seen in Theodore Roosevelt National Park in North Dakota.

Several rivers and their tributaries slice through the continent of North America. The rivers are important sources of water for the inhabitants of the continent. The rivers have also influenced the ecosystem and to some extent the climate of North America. The rivers of North America are of varying lengths with some as long as over 6,000 kilometers. The length of the river can be determined by several factors including the source of the river, the definition of the mouth of the river, and the scale of measurement. Therefore, the lengths of most of the rivers are just estimates.

The Three Longest Rivers in North America

Mississippi-Missouri-Jefferson Rivers

The longest river in North America comprises the continuous flow of Mississippi-Missouri-Jefferson Rivers. The river has a total length of 36,275 kilometers. Missouri River is the longest river in the continent and flows for 3,767 kilometers before joining the Mississippi River which is entirely in the US. Mississippi is approximately 3,374 kilometers and flows into the Gulf of Mexico. Jefferson is a tributary of Missouri River. It is approximately 134 kilometers long. The Mississippi-Missouri-Jefferson has a drainage area of 2.98 million square kilometers and drains the US and Canada.


Mackenzie-Slave-Peace-Finlay forms the second longest continuous river flow in North America, flowing for approximately 4,241 kilometers. Finlay River is approximately 402 kilometers long that flows through British Columbia and joined with Parsnip River to form Peace River. The Peace River flows for about 1,923 kilometers and joins the Athabasca River to form the Slave River. Slave River is a tributary of Mackenzie River which is the longest river in Canada, measuring 4,241 kilometers long from the Great Slave Lake to the Arctic Ocean. Mackenzie-Slave-Peace-Finlay drains an area of approximately 1.79 million square kilometers.


Yukon River flows from British Columbia in Canada through Yukon Territory into Alaska in the US and empties into the Bering Sea. The river is 3,190 kilometers long, the third longest in North America, and drains an area of approximately 850,000 square kilometers in the US and Canada. Saint Lawrence-Great Lakes join to form a river flow measuring 3,058 kilometers long. The Saint Lawrence River flows from Lake Ontario and joins with the Great Lakes while traversing the Canadian provinces. Saint Lawrence-Great Lakes drains an area of approximately 1 million square kilometers in the US and Canada. The Rio Grande, with a length of 3,051 kilometers, completes the list of five longest rivers in North America. The river drains an area of 570,000 square kilometers and flows through the US and Mexico. Other notable rivers in North America are Nelson-Saskatchewan, Arkansas, Colorado, Columbia, and Red. These rivers measure at least 2,100 square kilometers and drain a significantly large area.

Significance of the North American Rivers

North America has many more large and small rivers. The rivers are immensely important for the economy and sustaining the relatively large population. The rivers are important sources of fresh water, act as transport routes, and sources of water for irrigation. Several dams have been constructed along these rivers to help in the generation of hydroelectric power. Some of the rivers are also important tourist attraction sites, owing to their interesting geographical features.

The Longest Rivers in North America

Rank´╗┐RiverLength (km)
4Saint Lawrence-Great Lakes3,058
5Rio Grande3,057

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