State and federal lands are easy to locate on the internet. Also, certain communities may own "conservation land" that is open to hunting. If you're in an area that gets logged or mined, sometimes logging companies or mining companies allow access as long as you get a permit. I hunted reclaimed mine land in Ohio like that. Also, in MI, there is a state program that private owners can enroll in that gives them a tax break for keeping land forested. In turn, these lands must be open to hunting.

What is the law in Wisconsin regarding access to private property? Is permission required? In NH where I grew up it was not, but in IN where I live now, it is.

Most state wildlife agencies publish a rule book that will give some leads to places to hunt.