Wis. Stat. § 346.922: Transporting children in cargo areas of motor trucks.

(1) Notwithstanding s. 346.92, no person may operate upon a highway a motor truck having a gross weight of 10,000 pounds or less when any child under the age of 16 years is in an open cargo area of the motor truck.

(2) Subsection (1) does not apply to any of the following:

(a) A person operating a farm truck in conjunction with farm operations.

(b) A person operating a motor truck in a parade sanctioned by a local municipality.

(c) A person operating a motor truck for the purpose of transporting licensed deer hunters during the authorized deer hunting season with firearms.