river vs Podkamennaya Tunguska River

river and Podkamennaya Tunguska River both are nouns.

Word	Noun	Adjective	Verb	Adverb
river	Yes	No	No	No
Podkamennaya Tunguska River	Yes	No	No	No

river (noun)	Podkamennaya Tunguska River (noun)
a large natural stream of water (larger than a creek)	a river in Siberia that flows northwest to become a tributary of the Yenisei River