Ok after going to the MN state fair today(for my birthday). I SAW NO SIGNS POSTED(at the entrance i used), regarding carrying firearms. I still opted to conceal so as not to scare the herd.
Blackhawk SERPA holster(no paddle) and long loose t-shirt seemed to work just fine.
A good time was had by all. I recommend the scotch eggs, deep fried twinkies, mushroom and swiss brauts as well as corn fritters and fried green tomatos. Delicious!