Soudan Underground Mine State Park

Infobox_nrhp | name =Soudan Iron Mine
nrhp_type =nhl


caption =The 27th level of the Soudan Mine
location=Tower-Soudan State Park
nearest_city= Tower, Minnesota
lat_degrees =
long_degrees =
area =
built =1900
architect=
designated = November 13, 1966
added = November 13, 1966
governing_body = State
refnum=66000905cite web|url=http://www.nr.nps.gov/|title=National Register Information System|date=2007-10-03|work=National Register of Historic Places|publisher=National Park Service] citation|title=PDFlink| [http://pdfhost.focus.nps.gov/docs/NHLS/Text/66000905.pdf National Register of Historic Places Inventory-Nomination: Soudan Underground Mine State Park] |303 KiB |author=Stephen Lissandrello |date=January 3, 1976 |publisher=National Park Service and PDFlink| [http://pdfhost.focus.nps.gov/docs/NHLS/Photos/66000905.pdf Accompanying 8 images from 1975.] |897 KiB ]

The Soudan Underground Mine State Park is a Minnesota state park at the site of the Soudan Underground Mine, on the south shore of Lake Vermilion. The mine is known as Minnesota's oldest, deepest, and richest iron mine, and now hosts the Soudan Underground Laboratory.

History

In the late 1800s, prospectors searching for gold in northern Minnesota discovered extremely rich veins of hematite at this site, often containing more than 65% iron. An open pit mine began operation in 1882, and moved to underground mining by 1900 for reasons of safety. From 1901 until the end of active mining in 1962, the Soudan Mine was owned by the United States Steel Corporation's Oliver Iron Mining division. By 1912 the mine was at a depth of 1,250 feet (381 m). When it closed, level 27 was being developed at 2,341 feet (713.5 m) below the surface. US Steel then donated the Soudan Mine to the State of Minnesota to use for educational purposes.

The primary underground mining method used was known as cut and fill. This involved mining the ceiling and using Ely Greenstone and other waste rock to artificially raise the floor at the same rate as the ceiling was being mined out. As a result the floor and ceiling were always 10-20 feet (3-6 m) apart, and waste rock never had to be hauled to the surface, since it was recycled. This was not possible in the Ely mines because their iron formations were not as solid as those in Soudan.

tate Park

The park is in Breitung Township, on the shore of Lake Vermilion in northern Minnesota's Vermilion Range. The mine is close to Minnesota State Highway 169, about 20 miles east of Virginia and 20 miles (30 km) west of Ely, or about one mile from Tower. It has become a popular tourist site, often visited on the way to and from Ely and the Boundary Waters Canoe Area Wilderness.

The state park is operated under the Department of Natural Resources. It is a National Historic Landmark, meaning that it is also listed on the National Register of Historic Places. The surface buildings are open to the public, and during the summer months there are daily tours of the mine. Visitors are lowered in an 80-year-old electric mine hoist to level 27, the mine's lowest level at 2,341 feet (713.5 m) below ground. Two tours are open to the public: one that explores the historic mining facilities, and another that focuses on the currently active underground physics laboratory.

Underground Laboratory

In the 1980s, scientists from the University of Minnesota began to develop the Soudan Mine as a site for sensitive physics experiments because of the very low rate of cosmic rays in the deep underground site. The mine was originally home to the Soudan 1 proton decay experiment and its successor, Soudan 2. The University and the Department of Natural Resources have since expanded the laboratory to accommodate other physics projects, such as the currently active MINOS neutrino detector, CDMS-II, a dark matter search experiment, and work on electro forming copper to create pure radiation free copper. Low-background materials screening facilities are in use and continuing development, and the mine has been proposed as one possible site for a U.S. Deep Underground Science and Engineering Laboratory. Parts of the laboratory are open for daily tours, and there is an annual open house with more access to the facilities and representatives of the experiments to help with the tours and answer questions.

References

External links

* [http://www.dnr.state.mn.us/state_parks/soudan_underground_mine/index.html Soudan Underground Mine State Park]
* [http://nrhp.mnhs.org/property_overview.cfm?propertyID=1 National Register of Historic Places: Mines: Soudan Mine]
* [http://www.soudan.umn.edu/ Soudan Underground Laboratory]
* [http://www.int.washington.edu/DUSEL/ Deep Underground Science and Engineering Laboratory] (proposed)
* [http://www.towersoudan.com/ Tower Soudan Historical Society]
* [http://tps.cr.nps.gov/nhl/detail.cfm?ResourceId=685&ResourceType=Site NHL summary]