All snowmobiles used in Iowa must also have a DNR user permit. Both residents and non-residents can obtain user permits at a county recorder's office or via the online system. There is no special licensing requirement for snowmobile riders. However, riders who are 12 to 17 years-old must have completed an approved snowmobile safety course and carry the completion certificate with them anytime they are riding. This regulation is enforced for both resident and non-residentriders. Riders under 12, or riders under 18 who do not have a safety certificate, must be under the direct supervision of an adult.
Check out these Nemaha, IA ATV/OHV resources: