The registration window opened Sept. 1 and closes Dec. 31 for owners to register their all-terrain vehicles (ATVs), off-road utility vehicles (ORVs), off-road motorcycles (ORM), and snowmobiles. The Iowa DNR asks ATV, ORV, ORM and snowmobile owners to pair timely registrations with safe riding practices. To drive these vehicles on public roads in Iowa, drivers must be at least 18 years old with a valid driver’s license. In addition to use of public roadways, the Iowa DNR is generally seeing increased interest in driving off-road vehicles. While properly-equipped off-highway vehicles can be operated day or night using headlights, there are only certain Iowa roadways that are legally accessible.