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Iron mining in Wisconsin

location and depth of carbonate bedrock in Wisconsin

Background on mining regulations and resources

Overview of metallic mineral regulation in Wisconsin, third edition (Special Report 13), 2004, Thomas J. Evans

Mineral and water resources of Wisconsin, 1976, prepared by the US Geological Survey in collaboration with the Wisconsin Geological and Natural History Survey

Iron mining in Wisconsin, 2011, Wisconsin Geological and Natural History Survey Factsheet 3. Formatted version of the map and text on this page.

Metallic mineral deposits, 2011, Wisconsin Geological and Natural History Survey Factsheet 4.

Mining information sheets, prepared by the Wisconsin Department of Natural Resources to explain metallic mining regulations in Wisconsin. Includes information about the permitting process, how the DNR regulates metallic mining, local decisions, and reclamation issues and requirements.

Types of iron ore

Iron ore is present in a number of places and geologic settings within Wisconsin. Iron ore can be defined on the basis of its iron content into low-grade ore (taconite), which commonly contains 25 to 35% iron, and high-grade ore, which contains 50 to 70% iron.

Iron-bearing ore minerals include oxides, carbonates, silicates, and, in some cases, sulfides. In Wisconsin, the most important iron ore minerals are oxides: magnetite (Fe3O4), hematite (Fe2O3), and goethite/limonite (Fe2O3•H2O).

Brief overview of Wisconsin’s iron mining history

Limited amounts of high-grade iron ore were first mined in Wisconsin in the 1850s in the Black River Falls District of Jackson County and the Ironton area of Sauk County. More substantial iron mining of high-grade ore began in the Gogebic and Florence Districts in the 1880s and continued into the 1960s. Mining in the Baraboo District took place between 1904 and 1925. The Jackson County Iron Company re-opened mining in the Black River Falls District in 1969 when they began extracting low-grade taconite ore that was beneficiated (concentrated) and pelletized on site. The mine ceased operations in 1983 and was reclaimed.

Development opportunities

Significant remaining tonnages of lower grade ore have been identified by magnetic surveys and limited core drilling in several of the aforementioned districts, most notably the Gogebic District in Iron and Ashland Counties. Future development will depend on economic and environmental considerations.

Related links

Mining in Wisconsin, 3-part series, Wisconsin State Journal, October 8–11, 2011

EPA approves Bad River Tribe's bid to regulate water quality, Journal Sentinel, October 5, 2011

Senate committee on mining jobs announced, wispolitics.com, September 29, 2011

Public forum on mining laws, hosted by the State Bar of Wisconsin, includes video of the symposium, September 14, 2011

Corps of Engineers weighs in on possible changes to Wisconsin mining laws, Journal Sentinel, September 17, 2011

Public meeting on proposed Penokee Iron Mining project, hosted by Wisconsin Public Radio, includes audio of the full meeting and slides of presentations by Thomas J. Evans and Bruce Brown of the Survey (overview of Wisconsin's regulatory process and iron mining resources in the western Gogebic Range), January 19, 2011



Survey contacts

James Robertson 608/263.7384 jmrober1@wisc.edu Geology of Wisconsin
Esther Stewart 608/263.3201 esther.stewart@wgnhs.uwex.edu Mining