How long is the river aare?

There is no "minimum length" to be classified as a river. However, width, and to a lesser extent depth do figure into whether or not it is called a river. If one can toss a rock across it, and it is...

it will get longer by washing over where it starts or ends, moving the soil to grow.

From its source to its mouth. .............................................................................. If you didn't find that helpful, which most of you should not, the longest river is the...

10,00000,000000,000000 miles long and its 2000000,0000000,00000 miles wide

The river is 1980 miles (3190 km) long and empties into the Bering Sea. And no one knows when it starts to be a river.