Indigirka River vs river

Indigirka River and river both are nouns.

Word	Noun	Adjective	Verb	Adverb
Indigirka River	Yes	No	No	No
river	Yes	No	No	No

Indigirka River (noun)	river (noun)
a river in far eastern Siberia that flows generally northward to the Arctic Ocean	a large natural stream of water (larger than a creek)