I found this historical nugget online:
"The name (Mount David) was given by Forest Supervisor A. H. Sylvester. He also named Mount Jonathan, a mile to the west, linking the two peaks with Biblical history."
From the Bible: "The soul of Jonathan was knit with the soul of David."
Contrary to popular belief, Mount David and Mount Jonathan were not named after poets. But Whittier, Longfellow, Poe, and Irving definitely were.