My answer would be Cooperstown, though they are owned by Duvel.
According to wiki :
Don Feinberg sold Ommegang in 2003 to Belgian brewer Brouwerij Duvel Moortgat, brewers of the world-renowned Duvel Golden Ale. As a result, Ommegang Ales are made both in Belgium and in Cooperstown, New York. Duvel Moortgat brewed limited amounts of beer for Brewery Ommegang in 2006 to help meet demand, but has not brewed any since then.
So is Hennepin brewed in NY or in Belgium? - I'd swear the labels say brewed in Belgium