There are a large number ranging in size. The links below will give you a broad overview.
The longest river in Trinidad and tobago is THE ORTOIRE RIVER
A river can be as long as a country! For example the Mississippi River is almost as long as the U.S vertically.
The river Alt is 28kilometers long.
The Charles River is about 81mi long.
The Missouri River is 2,341 miles long and is the longest tributary to the Mississippi River.
the river nile it is 6695 km long
The River Wharfe is a river in Yorkshire, England and is 60 miles long.
The river ouse is 5 miles long
River crouch is 17.5 miles long
The Benue River Is 1400 Km Long
the missisipi river is 1,000,587,98 feet long.