it is called the mouth of the river
spring
77
the source is the start of a river
River Indus.
Missippi River
That would be the Indus River.
The source
The Illinois.
river
Feather River is a river in California. Flinders River is a river in Australia.
River Clyde in Scotland
Xi River is the name of a river in China. Xingu River is the name of a river in Brazil.