I have just taken a look at the Morman Family History Centre website.. which gives some new info on the McCulloughs. It reports that Ephraim's parents were James McCullough, born 1798 in Scotland, and Jeanette Rogers, born c1802 in Scotland.
New info for Ephraim himself indicates he was born 15 May 1824 in Island Magee, Antrim, Ireland. He died 28 May 1907 in Manistique.