Wisconsin Statutes § 948.605(2)(a) Any individual who knowingly possesses a firearm at a place that the individual knows, or has reasonable cause to believe, is a school zone is guilty of a Class I felony.
In Wisconsin the loaded or unloaded condition of a weapon is moot to the meaning. There are peculiar transport laws that relate to particularly hunting in Chapter 167.
In Wisconsin the document is a license and a prerequisite is training detailed at
Be wary of 'trainers' that charge for their services, particularly cops, as they are not bound to the truth, they are excused for errors made in good faith. My local cop teaches only the prohibitions but not the allowed exceptions. Locally trained neighbors do not know how to carry on a licensed premisis, for instance.