Denali vs Mount McKinley

Denali and Mount McKinley both are nouns.

Word	Noun	Adjective	Verb	Adverb
Denali	Yes	No	No	No
Mount McKinley	Yes	No	No	No

As nouns, Denali and Mount McKinley are synonyms defined as:

Denali and Mount McKinley: a mountain in south central Alaska; the highest peak in North America (20,300 feet high)

Other synonyms of Denali include McKinley, Mt. McKinley.

Denali (noun)	Mount McKinley (noun)
a mountain in south central Alaska; the highest peak in North America (20,300 feet high)	a mountain in south central Alaska; the highest peak in North America (20,300 feet high)