Which river has the largest drainage basin in North America?. The river with the largest drainage basin in North America is Mississippi–Missouri–Jefferson–Beaverhead–Red Rock–Hell Roaring which receives inflows from a basin area of 2,980,000 square kilometers in United States (98.5%), Canada (1.5%) and flows out primarily to the Gulf of Mexico. At second and third, are Mackenzie–Slave–Peace–Finlay with a drainage basin of 1,790,000 km2 and outflows to Beaufort Sea, and Nelson–Saskatchewan that receives inflows from a basin area of 1,093,000 km2.
( A drainage area is any area of land where precipitation collects and drains off into a common outlet, such as into a river, bay, or other body of water. )
Here are North America's largest rivers by drainage areas.
Mississippi–Missouri–Jefferson–Beaverhead–Red Rock–Hell Roaring is the longest river in North America at 6,275 kilometers (3,899 miles).
At 6,275km (3,899 miles), the Mississippi–Missouri–Jefferson–Beaverhead–Red Rock–Hell Roaring river system is the longest in North America, helmed by the two longest rivers in the United States, the Missouri river (3,768 km) and the Mississippi River (3,544 km).The Missouri River is the longest river in North America. Originating from the Rocky Mountains of western Montana, the Missouri flows east and south for 2,341 miles (3,767 km) before merging into the Mississippi River. The Mississippi River has its sources at Lake Itasca and Brower's Spring in Montana, and stretches for another 3,544km southwards before flowing out eventually to the Gulf of Mexico.
The drainage area of the river spans 2,980,000 square kilometers and discharges at a rate of 16,792m3. The deepest part of the Mississippi River is in New Orleans, where its depth could reach 200 feet (61m).
Mackenzie–Slave–Peace–Finlay is the 2nd longest river in North America at 4,241 kilometers (2,635 miles).
Mackenzie–Slave–Peace–Finlay is a river that stretches 4,241 kilometers (or 2,635 miles) in length, draining from a 1,790,000 km2 basin in Canada.
Its average discharge rate is 10,300 m3/3 and the river flows out into Beaufort Sea.
Nelson–Saskatchewan is the 3rd largest river by drainage area in North America at 1,093,000 km2.
Nelson–Saskatchewan is a 2,570-km long (1,597 miles) river that drains from a 1,093,000-km2 wide basin in Canada and United States.
Nelson–Saskatchewan discharges at 2,575 m3/3 and flows out into Hudson Bay.
Saint Lawrence–Great Lakes is the 3rd largest river by average discharge rate in North America at 10,100 m3/s.
Saint Lawrence–Great Lakes is a river that is 3,058 kilometers (or 1,900 miles) long and drains from a 1,030,000 km2 drainage basin in Canada (52.1% of river) and United States (47.9%).
Its average discharge rate is 10,100 m3/3 and the river flows out into Gulf of Saint Lawrence.
Yukon is the 3rd longest river in North America at 3,185 kilometers (1,979 miles).
Draining from an area as wide as 850,000 km2 in United States (59.8% of river) and Canada (40.2%), Yukon has a length of 3,185 kilometers (1,979 miles).
Yukon discharges at 6,210 m3/3 and flows out into Bering Sea.
Draining from an area as wide as 570,000 km2 in United States (52.1% of river) and Mexico (47.9%), Rio Grande has a length of 3,057 kilometers (1,900 miles).
Rio Grande discharges at 82 m3/3 and flows out into Gulf of Mexico.
Draining from an area as wide as 505,000 km2 in United States, Arkansas has a length of 2,348 kilometers (1,459 miles).
Arkansas discharges at 1,066 m3/3 and flows out into Mississippi River.
Ohio–Allegheny is the 3rd largest river by average discharge rate in United States at 7,957 m3/s.
Ohio–Allegheny is a 2,102-km long (1,306 miles) river that drains from a 490,603-km2 wide basin in United States.
The average volume of water flow is 7,957 m3/3 and the river flows out into Mississippi River.
Columbia is a river that is 2,250 kilometers (or 1,398 miles) long and drains from a 415,211 km2 drainage basin in United States and Canada.
Columbia discharges at 7,500 m3/3 and flows out into Pacific Ocean.
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