Growing Hops in Minnesota

I'm concerned about the brewing hops shortage and my parents' hobby farm is looking for a new crop. We've got about 3.5 acres along the Blue Earth River in Southern Minnesota.... water on two sides of the field... from the looks of it a typical harvest for an acre of hops is ~1500-1800 lbs of hops with a maximum of 2200 lbs / acre. Seems like 50-70% of that is typically usable. Anyway -- does anybody have some good information -- the only full season hop growth and harvesting I've ever seen done is at Barley John's... they don't seem to do much to the hops during the summer and then everybody just handpicks garbage bags full of hops in the fall. Obviously it's more complicated than that... but with hops reaching $13/lbs and my mom looking for something to do -- this might be possible. Especially with lots of cheap seasonal labor available in the area. This seems to be a good article, but not a lot about "Upper Midwest" growing. http://www.hort.purdue.edu/newcrop/afcm/hop.html I suppose I should start digging around on the UofM sites. Ryan