river vs Little Bighorn River

river and Little Bighorn River both are nouns.

Word	Noun	Adjective	Verb	Adverb
river	Yes	No	No	No
Little Bighorn River	Yes	No	No	No

river (noun)	Little Bighorn River (noun)
a large natural stream of water (larger than a creek)	a river that flows from northern Wyoming into the Bighorn River in southern Montana; site of Custer's Last Stand