Wis. Stat. § 191.06: Railroad extensions; certificate and notice necessary.

If any railroad company organized prior to July 1, 1907, shall desire to extend its lines in this state or to build branches connected therewith, or to construct any portion of its authorized line of railroad, it shall, before beginning construction thereof, obtain a certificate of convenience and necessity authorizing the construction; but it shall not be necessary to publish the articles of such railroad.