Wis. Stat. § 190.15
The commissioners of public lands may sell and convey to any railroad corporation, for the compensation and upon the terms that the commissioners may fix, a strip of land 100 feet wide, or more, if needed, through lands owned by the state that the commissioners have power to sell, and across which a railroad has been or shall be located or constructed. The railroad corporation shall, as soon as the route of its road is definitely fixed, deposit in the office of the commissioners of public lands a plat exhibiting all of the affected public lands and the location of the route through the affected public lands. The railroad corporation shall have no right to take or use any of the affected public lands prior to depositing the plat. Every deed or patent for any lands conveyed to a railroad corporation under this section shall contain an express reservation unto the state of the title of the lands conveyed except as to the use of the lands by the railroad corporation or its successors or assigns for railroad purposes.
Wis. Stat. § 190.15