river vs Gila River

river and Gila River both are nouns.

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

river (noun)	Gila River (noun)
a large natural stream of water (larger than a creek)	a river that rises in western New Mexico and flows westward through southern Arizona to become a tributary of the Colorado River