river vs Vetluga River

river and Vetluga River both are nouns.

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

river (noun)	Vetluga River (noun)
a large natural stream of water (larger than a creek)	a river in central Russia; flows generally southward into the Volga