Where does the river forth start and end?

Answer 1

It begins at its source and ends at the mouth of the river.
A river might begin in a lake, in an underground water reservoir, as melting water from a glacier or as many small streams come together and form a bigger stream you might call a river.

Answer 2

river starts at a "source" and ends at a "mouth".

Answer 3

It depends on what river you're talking about

Answer 4

It starts at the source and ends at the mouth.

Answer 5

A river starts in a mountain area and drains into a larger river if it is a tributary river, or it ends directly at an ocean or bay.

Answer 6

Source or headwater