The source or beginning of a river is called the 'headwater'. The beginning of a river is known as the source.
To find where the beginning of a river is.
River Indus.
the source of the river
That would be the Indus River.
Missippi River
Grumeti River
Xingu River
Feather River is a river in California. Flinders River is a river in Australia.
Colorado River, columbine riverIllinois River
spring
the source is the start of a river