river vs Willamette River

river and Willamette River both are nouns.

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

river (noun)	Willamette River (noun)
a large natural stream of water (larger than a creek)	a river in western Oregon that flows north into the Columbia River near Portland