Important Things to Know
The University of Hawaii at Hilo College of Hawaiian Language recommends one word, "Maunakea" as the proper Hawaiian usage. Maunakea is a proper noun—the name of the mountain on the Island of Hawaii. "Mauna Kea" spelled as two words is really referring to any white mountain—it is a common noun (vs. the proper noun).
Another example of a common noun to a proper noun in Hawaiian is "ka pua". Spelled separately it refers to "the flower" or any flower. Spelled as "Kapua", it refers to the "proper name" of someone/something.
For more information, visit the `Imiloa website.