Hey, Mr. Matt:
Where are you from if you're from the boonies?
-- My Hometown, the Boonies
Nobody was from the boonies before the mid-1960s or so. That's when the word "boondocks" was shortened to "boonies," since everybody's attention span was pretty short back then. "Boondocks" is a WWII-era borrow from the Philippines: bundok, which means "mountain."