which is the longest river in the world
Answers
Rivers of the World: World's Longest Rivers
Take a look at a map of the United States or of any country in the world. Notice how towns and cities tend to be located next to rivers? This is no coincidence. Rivers provide water for the essential needs of both tiny towns and huge cities. There's a good chance that you live near one of our nation's large rivers. Ever wonder what rivers are the longest? Look at the graphic below to see our short list of long rivers.
(It's not so easy to define how long a river is. If a number of tributaries merge to form a larger river, how would you define where the river actually begins? Here is how we are defining river length:
River lengths or river-length data are affected not only by some of the natural and artificial causes noted in the preceding paragraph, but also by the precision of various techniques of measurement, by the scale of available maps or aerial photographs, and by somewhat arbitrary decisions. For example, the length may be considered to be the distance from the mouth to the most distant headwater source (irrespective of stream name) or from the mouth to the headwaters of the stream commonly identified as the source stream. The names of some rivers, such as the Mississippi River and the Rio Grande, are unchanged from source to mouth. In contrast, the name of the source of the Mobile River—Tickanetley Creek—changes five times before becoming Mobile River 45 miles north of Mobile Bay.
WORLD
Nile: 4,132 miles
Amazon: 4,000 miles
Yangtze: 3,915 miles
UNITED STATES
Missouri: 2,540 miles
Mississippi: 2,340 miles
Yukon: 1,980 miles
Rio Grande: 1,900 miles
St. Lawrence: 1,900 miles
Arkansas: 1,460 miles
Colorado: 1,450 miles
Atchafalaya: 1,420 miles
Ohio: 1,310 miles
Red: 1,290 miles
Brazos: 1,280 miles
Columbia: 1,240 miles
Snake: 1,040 miles
Platte: 990 miles
Pecos: 926 miles
Canadian: 906 miles
Tennessee: 886 miles
Colorado (of Texas): 862 miles
North Canadian: 800 miles
Mobile: 774 miles
Kansas: 743 miles
Kuskokwim: 724 miles
Yellowstone: 692 miles
Tanana: 659 miles
Milk: 625 miles
Ouachita: 605 miles
Hamilton: 600 miles
Cimarron: 600 miles
(Source: Kammerer, J.C., Largest Rivers in the United States, US Geological Survey Open-File Report 87-242 rev. 1990)
Sources and more information
The Nature of Water: Environment Canada