Rivers in the United States
A watershed is a region into a river that comes from a high point to a low point and flows into a large body of water.
The source of a river or stream is the furthest place in that river or stream from its estuary or confluence with another river, as measured along the course of the river.
A mouth/delta is an area formed from the deposition of sediments at the mouth of a river.
A Great Basin is a watershed that does not flow into the ocean.
A divided river is something that separates the larger rivers.
A headwater is an extreme upper reaches of a stream. Headwaters has light that are blocked by trees making the plant life stream scarce.
A down river is something between the headwaters and flood plains.
A tributary a river or stream flowing into a main river or stream.