river vs Mohawk River

river and Mohawk River both are nouns.

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

river (noun)	Mohawk River (noun)
a large natural stream of water (larger than a creek)	a river of central New York that flows southeastward to the Hudson River