Gila River vs river

Gila River and river both are nouns.

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

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