Had some incredible mallard shoots on public land in NW MN in the late 90s/early 2000s when I was a teen. Can't imagine how good central ND must have been during that time.
MN still shoots a pretty good number of ducks (I think they still have the highest number of duck hunters) but the opportunities are so much different in ND. In MN you're probably on overhunted public waters if you don't have access to private land, or you're setting up on a lake and hoping that ducks come by. ND you can actually try to scout and pick decent spots. Go on some of the MN forums and read about guys getting to boat accesses at 3 am only to find several other trailers.
MN seems to lack the small potholes that really produce and harbor ducks. They have plenty of water but you read a lot about how water quality has gone downhill as water levels have gone up and farming has intensified. Seems like there is so little nesting habitat in most of the prairie areas I've been to in MN; everything is farmed.