Not much is known about this group. I've come across the information about these mounds incidentally while reading about Gasner Hollow State Natural Area in the book Wisconsin Naturally published by the DNR. There is no beaten path to the mounds - only faint trail leading up to the top of the bluff, after you park on the shoulder of Gasner Hollow Road just north of Bagley, Wisconsin. Once on top,
mounds are fairly easy to see right on the crest of the bluff in the open woods. There seems to be half dozen of them or so - it's hard to
say for sure since vegetation thickens as you continue north on the bluff. Most of them look like linears, but one might be a conical
(it could be a linear cut in half too). Mounds are away from human disturbance, but have trees and shrubs growing on them.