Black Hills vs chain of mountains

Black Hills and chain of mountains both are nouns.

Word	Noun	Adjective	Verb	Adverb
Black Hills	Yes	No	No	No
chain of mountains	Yes	No	No	No

Black Hills (noun)	chain of mountains (noun)
mountains in southwestern South Dakota and northeastern Wyoming; sacred to the Sioux (whites settling in the Black Hills led to the Battle of Little Bighorn); site of Mount Rushmore	a series of hills or mountains