This is the current Iowa laws and rules booklet.

Depends on what you want to use the UTV for.  

Recreational use has to be registered. Some ATV parks allow UTV use. Phase II (opening soon) at Gypsum City in Fort Dodge will provide some of the best riding in the midwest.

Farm use has exemptions.

Counties and towns may allow use on roads for others. Some have and others have not.  As of now, each county can have their own laws and they are not the same as the next county.  No state wide laws yet. The Iowa Ohv Association is trying to get the law changed so the rules are the same statewide. Also on Facebook

Let me know if you need more info.

John