Tributary

From Simple English Wikipedia, the free encyclopedia

The thick blue line is the river. The thin blue line is its tributary.
The thick blue line is the river. The thin blue line is its tributary.

A tributary of a river is another river that flows into it. If one river flows into a second river, then the first river is a tributary of the second river.

For example, in the United States the Missouri River flows into the Mississippi River. That means the Missouri River is a tributary of the Mississippi River.

A river and all its tributaries form the catchment of that river.

A watershed separates the catchments of separate rivers.