I used to hunt with folks in WI. They would guarantee hunts. They would put up massive ladder/pedastal stands and then begin bringing in truck loads of corn and pile it up a couple of feet high and 50 feet in diameter.....
The deer would congregate on these food piles for weeks before the season began. Hundreds. You can’t mill around in large numbers like that and not have an infected herd.
MN hasn’t allowed that sort of behaviour for many years, and we don’t have that problem.
I’ve seen it in WI. It did happen.
I don’t doubt you, and I don’t remember the regulations when baiting was legal in the southern zones, but my recollection is that it wasn’t much different that what it is today in the north, a few gallons at a site, or mechanical feeders which are banned now. Truckloads of corn, I suspect that was an abberation. Hopefully someone with a better memory will come along, I may have some old regulations saved which I can check tomorrow.