Isle Royale National Park vs Isle Royal National Park

Isle Royale National Park and Isle Royal National Park both are nouns.

Word	Noun	Adjective	Verb	Adverb
Isle Royale National Park	Yes	No	No	No
Isle Royal National Park	Yes	No	No	No

As nouns, Isle Royale National Park and Isle Royal National Park are synonyms defined as:

Isle Royale National Park and Isle Royal National Park: a national park on an island in Michigan; includes prehistoric iron mines

Isle Royale National Park (noun)	Isle Royal National Park (noun)
a national park on an island in Michigan; includes prehistoric iron mines	a national park on an island in Michigan; includes prehistoric iron mines