You can legally ride a registered ATV on streets, roads, and highways—except for interstates and controlled access highways—in North Dakota, as long as the speed limit is not posted above 55 miles per hour. Licensed drivers age 16 and over can operate class III OHVs on highways posted up to 65 miles per hour. If an ATV cannot achieve a minimum speed of 30 miles per hour, it may not be used on a paved highway. You must have liability insurance to drive your ATV on public roads or lands.
Check out these Napoleon, ND ATV/OHV resources: