Wis. Stat. § 114.16: Pilots; federal license or permit.

It shall be unlawful for any person to pilot within this state any civil aircraft, unless such person is the holder of a currently effective pilot’s license or student’s permit issued by the government of the United States; but this restriction shall not apply to any person operating any aircraft licensed by a foreign country with which the United States has a reciprocal agreement covering the operation of such licensed aircraft.