Located west of HWY G, south of 7th street and north of 8th street north of Necedah, this group is a part of protected Cranberry Creek Archeological District and its namesake State Natural Area. There are supposed to be several hundred conical mounds, also including one bird and one bear effigies. I found few mounds in the northern part of the site as advised by Department of Natural Resources' webpage. The ones shown here are not in such a great condition - while one can clearly see that large trees were removed sometimes in the past, presently the mounds are being overtaken by all kinds of shrubbery and brush and are quite a sorry site.
I've seen photographs of the mounds apparently from the same location, but more likely showing the southern cluster of mounds (which I didn't find). Those looked much better, being situated in more open forest without much undergrowth. Mounds are not natural formations, and as such should not be left unmolested like old growth forest or pristine lake should. Instead, they require care and maintenance - or they'll be eventually claimed back by nature.