http://www.crexrealty.com/wild.htm
http://www.eaglestar.net/khlmr3-.html
http://www.wisconsinhuntinglandforsale.com/
You can buy this way (and probably pay top dollar aka too much) or you can do it the old fashion way. Drive to Wisconsin, find an area you think you might like, stop in and talk (respectfully, farmer like) to some farmers.
I bought land in the early 90's for $140.00 per acre. Wasn't listed, owner lived in a seemingly abandon house, deal was made on a hand shake. It was a "land contract" and I paid him several payments during the course of the year (per the agreement) and we went to the courthouse in the fall and it was mine. 103 acres @ 125.00 and 140.00 per acre depending on whether it was wooded (hardwoods) or pasture/fields.
Northern Wisconsin has some relatively inexpensive land. If you want it just for a getaway house and hunting look for non-pasture, woods, slashings, swamps.
There are deer all over Wisconsin, folks talk about some monsters coming out of area along the Mississippi South of Wabasha down to the IL border.
Public land in Wisconsin isn't like what I've seen of Maryland public land. Up there I've hunted places for several days and didn't see another hunter. If you're seeing a lot of other hunters you're in the wrong place.