There is a MN DMV office/desk in the pharmacy in Grand Marais, and I think there is one in Silver Bay as well.
Grand Marais DMV I got a new registration for my canoe there last year.
Word of caution - maybe a sub was there that day - but with my new canoe registration I was wrongly told I needed to go to the hardware store to buy display numbers for my canoe. When I pushed back I was simply shown a picture in the little book showing where to put numbers on a canoe - but that is only if motorized. Of all places in the world to get that wrong!