Wis. Stat. § 350.045: Public utility exemption.

So that public utilities may effectively carry out their obligations to the public, the restrictions imposed by this chapter relating to use on, near or adjacent to highways shall not apply to snowmobiles operated to fulfill the corporate function of the public utility in those cases where safety does not require strict adherence to the regulations related to snowmobiles in general. However, snowmobiles operated by public utilities must be operated in a safe manner at all times.