Irving, R.D., 1880, Map of Wisconsin and adjoining portions of Michigan, Illinois, Iowa, and Minnesota, showing geological structure, positions of the principal mineral districts, rail road connections, etc., etc.: Part of mineral resources of Wisconsin: Transactions of the American Institute of Mining Engineers, vol. VIV, pp. 478–508.
Ask A Geologist
Questions about Wisconsin geology? We've got answers!
Contact one of our experts for an answer from a real, live geologist.
3817 Mineral Point Road
Madison, Wisconsin 53705-5100