If you’re visiting Minnesota, and your ATV is registered in another state or country, you will not need to purchase a Minnesota registration unless you plan to stay in the state for more than 30 days. If you come from a state that doesn't register ATVs, you will need to register your vehicle in Minnesota.
Visitors who want to operate an ATV that's not registered in Minnesota on a state trail, will need to purchase a non-resident OHV trail pass.Driver's license, helmet,ATV fit, and safety certificate rules apply to out-of-state visitors, as well.
Check out these Williams, MN ATV/OHV resources:
