Wis. Stat. § 847.01: Action by settler on public lands.

A settler on the public lands of the United States, under the laws thereof may maintain an action to recover possession of the lands settled upon or claimed, or an action for injury to, or interference with such lands. Such action may not be brought unless the land claimed is staked or otherwise marked out so that its boundaries can be readily traced and the extent of the claim known and unless the plaintiff occupies the land or has made improvements thereon to the value of $50. An action under this section, may not be brought if the land claimed exceeds 160 acres, located in one body or in different parcels, or if for 6 months next preceding the commencement of the action the plaintiff has not occupied or has neglected to cultivate the land claimed.