Actually, Lake Ontario cannot be the headwaters of the St. Lawrence since the lake itself has a source... The true headwaters would be spring that feeds the North River in Northern Minnesota, which runs to the St. Louis river and then into Lake Superior an onwards through the Great Lakes towards the St. Lawrence.
The word 'narrow' describes how wide a river is when it's near its source. The source of a river or stream is called a headwater.
Headwater is a term used to refer to the source of a river or stream's water supply. For example, some river's headwater source will be a lake, while other rivers may have an ocean feeding their water supply.
The source of a river
Headwater .
Headwater
Headwater or the source.
The starting point or origin of a river is known as the 'source' or sometimes the 'headwater'.
The source or beginning of a river is called the 'headwater'. The beginning of a river is known as the source.
A headwater is the place from which the water in the river or stream originates. It is also called the source of the river or stream
The usual terms are "source" and/or "headwaters."
Where a river starts often high in a mountain is called a headwater. It usually doesn't start in one specific place, but in many locations high in the mountains.
The mouth of the river is NOT called the start. The mouth is the end of a river. The headwaters refers to the starting point(s). The starting point is called the source.