When I read MI DNR rules, it says: A person who is at least 12 but less than 17 years of age must successfully complete a Michigan-approved snowmobile safety course if they will be: operating a snowmobile without the direct supervision of a person 21 years of age or older. (certificate must be in operator's immediate possession.) crossing any highway or street. (certificate must be in operator's immediate possession.) If your child is younger than 12 years old and can ride, how do you legally take him/her on the trails? If anything, the rule about crossing a street will come into play at most gas stops.