Please note that this land is privately held managed forest, which means the property owner gets a tax break and in return the land IS open to the public...so it is not private property as we know it.
http://dnr.wi.gov/topic/ForestLandowners/openToPublic.html
Damned DNR strikes again...
The one thing about government land claims, such as gold claims, is that a person can treat the property as private property. I suspect this company has a claim that is delineated by boundaries that they can operate as private property so long as the claim is open.