Wis. Stat. § 23.425: Environmental education.

(1m) The department may charge the participants in a departmental environmental education program fees to cover the costs of the program. The amount charged may not exceed the costs of conducting the program.

(2m) The fees collected by the department under sub. (1m) for the use of the MacKenzie environmental center shall be deposited in the general fund and credited to the appropriation under s. 20.370 (1) (gb).