river vs Housatonic River

river and Housatonic River both are nouns.

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

river (noun)	Housatonic River (noun)
a large natural stream of water (larger than a creek)	a river that rises in western Massachusetts and flows south through Connecticut to empty into Long Island Sound