Keweenaw Peninsula

File:Brockway Mountain Lake Superior.jpg, near Copper Harbor in Keweenaw County]]

The peninsula measures about {{Convert|150|mi}} in length and about {{Convert|50|mi}} in width at its base.

The ancient lava flows of the Keweenaw Peninsula were produced during the Mesoproterozoic Era as a part of the Midcontinent Rift between 1.096 and 1.087 billion years ago.{{Cite web |url=https://www.nps.gov/kewe/learn/nature/geologic-timeline.htm |title=Geologic Timeline - Keweenaw National Historical Park (U.S. National Park Service) |website=www.nps.gov |language=en |access-date=2018-06-08 |archive-date=2018-06-12 |archive-url=https://web.archive.org/web/20180612143121/https://www.nps.gov/kewe/learn/nature/geologic-timeline.htm |url-status=live }} This volcanic activity produced the only strata on Earth where large-scale economically recoverable 97 percent pure native copper is found.

Much of the native copper found in the Keweenaw comes in either the form of cavity fillings on lava flow surfaces, which has a ”lacy” consistency, or as "float" copper, which is found as a solid mass. Copper ore may occur within conglomerate or breccia as void or interclast fillings. The conglomerate layers occur as interbedded units within the volcanic pile.{{cite journal |url=http://www.nps.gov/history/history/online_books/geology/publications/pp/754-C/sec1.htm |last=Huber |first=N. King |year=1973 |title=The Portage Lake Volcanics (Middle Keweenawan) on Isle Royale, Michigan |journal=Geological Survey Professional Paper |id=754—C |doi=10.3133/pp754C |series=Professional Paper |page=13 |doi-access=free |bibcode=1973usgs.rept...13H |access-date=2011-01-22 |archive-date=2010-01-13 |archive-url=https://web.archive.org/web/20100113183903/http://www.nps.gov/history/history/online_books/geology/publications/pp/754-C/sec1.htm |url-status=dead }}

The Keweenaw Peninsula and Isle Royale, formed by the Midcontinent Rift System, are the only sites in the United States with evidence of prehistoric aboriginal mining of copper. Artifacts made from this copper by these ancient indigenous people were traded as far south as present-day Alabama.Public Law 102-543 (Oct. 27, 1992); 106 STAT. 3569 These areas are also the unique location where chlorastrolite, the state gem of Michigan, can be found.

The northern end of the peninsula is sometimes referred to as Copper Island (or "Kuparisaari" by Finnish immigrants), although this term is becoming less common.{{cite book |title=History of the Finns in Michigan |url=https://books.google.com/books?id=JcJVNoE3BuUC&q=%22Copper+Island%22+Michigan+origins&pg=RA1-PA442 |page=76 |last1=Holmio |first1=Armas K. E. |last2=Ryynanen |first2=Ellen M. |publisher=Wayne State University Press |isbn=978-0-8143-2974-0 |year=2001 |access-date=2008-09-28 |archive-date=2023-03-05 |archive-url=https://web.archive.org/web/20230305215202/https://books.google.com/books?id=JcJVNoE3BuUC&q=%22Copper+Island%22+Michigan+origins&pg=RA1-PA442 |url-status=live }} ''{{cite web |url=http://ethnicity.lib.mtu.edu/groups_Finns.html |archive-url=https://web.archive.org/web/20070308124318/http://ethnicity.lib.mtu.edu/groups_Finns.html |url-status=dead |archive-date=2007-03-08 |title=An Interior Ellis Island: Ethnic Diversity and the Peopling of Michigan's Copper Country, Keweenaw Ethnic Groups: The Finns |work=MTU Archives and Copper Country Historical Collection |publisher=J. Robert Van Pelt Library, Michigan Technological University}} It is separated from the rest of the peninsula by the Keweenaw Waterway, a natural waterway which was dredged and expanded in the 1860s{{cite web |url=http://www.exploringthenorth.com/houghton/main.html |work=Exploring the North |title=Houghton |access-date=2007-09-12 |archive-date=2007-09-28 |archive-url=https://web.archive.org/web/20070928023534/http://www.exploringthenorth.com/houghton/main.html |url-status=live }} across the peninsula between the cities of Houghton (named for Douglass Houghton) on the south side and Hancock on the north.

A Keweenaw Water Trail has been established around Copper Island. The Water Trail stretches approximately {{Convert|125|mi|4=-1}} and can be paddled in five to ten days, depending on weather and water conditions.{{cite web |url=http://www.kwta.org/ |title= Keweenaw Water Trail Association |access-date=2025-01-15}}

The Keweenaw Fault runs fairly lengthwise through both Keweenaw and neighboring Houghton counties. This ancient geological slip has given rise to cliffs. U.S. Highway 41 (US 41) and Brockway Mountain Drive, north of Calumet, were constructed along the cliff line.

{{gallery|mode=packed|align=center|width=135|height=135

|File:MichiganCopperIsland.svg|Copper Island in white

|File:Keweenaw structure.jpg|Cross-section of the Lake Superior basin showing the tilted strata of volcanic rock that form both the Keweenaw Peninsula and Isle Royale

|File:USGS Lake Superior syncline.png|Lake Superior syncline

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Lake Superior significantly controls the climate of the Keweenaw Peninsula, keeping winters milder than those in surrounding areas.{{cite web |url=https://www.nps.gov/kewe/index.htm |title=Keweenaw |publisher=US National Park Serive |access-date=21 October 2011 |archive-date=26 October 2011 |archive-url=https://web.archive.org/web/20111026194637/http://www.nps.gov/kewe/index.htm |url-status=live }} Spring is cool and brief, transitioning into a summer with highs near {{cvt|70|F|C}}. Fall begins in September, with winter beginning in mid-November.

The peninsula receives copious amounts of lake-effect snow from Lake Superior. Official records are maintained close to the base of the peninsula in Hancock, Michigan,{{cite web |url=http://www.mtu.edu/alumni/favorites/snowfall/snowfall.html |title=Snowfall Records |publisher=Michigan Technological University |access-date=21 October 2011 |archive-date=31 October 2011 |archive-url=https://web.archive.org/web/20111031165514/http://www.mtu.edu/alumni/favorites/snowfall/snowfall.html |url-status=live }} where the annual snowfall average is about {{cvt|220|in|cm}}. Keweenaw County reports daily snowfall, and monthly and seasonal totals since 2006.{{cite web|url=https://www.keweenawcountyonline.org/snowfall-full.php |title=Keweenaw County Snowfall |access-date=2025-01-15}} In the Keweenaw community of Delaware, an unofficial record gives an average of about {{cvt|240|in|cm}} (1957-2011) and the record snowfall for one season of {{cvt|390|in|cm}} in 1979.{{cite web |url=http://www.eagleharborweb.net/archive/kewsnorec.htm |title=Keweenaw Snowfall Record |publisher=Eagle Harbor Web |access-date=21 October 2011 |archive-date=29 October 2011 |archive-url=https://web.archive.org/web/20111029043201/http://www.eagleharborweb.net/archive/kewsnorec.htm |url-status=live }} Averages over {{cvt|250|in|cm}} certainly occur in the higher elevations closer to the tip of the peninsula.

{{gallery|mode=packed|align=center|width=135|height=135

|File:Keweenaw Snow Thermometer.jpg|Keweenaw Snow-mometer north of Mohawk on US 41

|File:ISS064-E-35655 - View of Michigan.jpg|Some shelf ice remains along the shore of the peninsula as most of the ice breaks away; taken at 11:12:06 AM Central Standard Time on February 20, 2021 from the International Space Station[https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS064&roll=E&frame=35655 ISS064-E-35655] {{Webarchive|url=https://web.archive.org/web/20220420035610/https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS064&roll=E&frame=35655 |date=2022-04-20 }}, Gateway to Astronaut Photography of Earth by the International Space Station program and the JSC Earth Science & Remote Sensing Unit, ARES Division, Exploration Integration Science Directorate

|File:ISS064-E-52399 Western Lake Superior and the Keweenaw Peninsula.jpg|Snow on the peninsula; taken at 2:05:48 PM CST on April 3, 2021 from the ISS[https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS064&roll=E&frame=52399 ISS064-E-52399] {{Webarchive|url=https://web.archive.org/web/20220420034015/https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS064&roll=E&frame=52399 |date=2022-04-20 }}, Gateway to Astronaut Photography of Earth by the International Space Station program and the JSC Earth Science & Remote Sensing Unit, ARES Division, Exploration Integration Science Directorate

|File:ISS061-E-4566 - View of Earth.jpg|Mostly sunny conditions over the peninsula, taken at 2:07:45 PM Central Daylight Time on October 8, 2019 from the ISS[https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS061&roll=E&frame=4566 ISS061-E-4566] {{Webarchive|url=https://web.archive.org/web/20220420034359/https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS061&roll=E&frame=4566 |date=2022-04-20 }}, Gateway to Astronaut Photography of Earth by the International Space Station program and the JSC Earth Science & Remote Sensing Unit, ARES Division, Exploration Integration Science Directorate

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File:Copper and calcite (Mesoproterozoic, 1.05-1.06 Ga; Pewabic Lode, Upper Peninsula of Michigan, USA) 3 (16679632374).jpg

Beginning as early as seven thousand years ago and apparently peaking around 3000 B.C., Native Americans dug copper from the southern shore of Lake Superior. This development was possible in large part because, in this region, large deposits of copper were easily accessible in surface rock and from shallow diggings. Native copper could be found as large nuggets and wiry masses. Copper as a resource for functional tooling achieved popularity around 3000 B.C., during the Middle Archaic Stage. The focus of copper working seems to have gradually shifted from functional tools to ornamental objects by the Late Archaic Stage c. 1200 B.C. Native Americans would build a fire to heat the rock around and over a copper mass and, after heating, pour on cold water to crack the rock. The copper was then pounded out, using rock hammers and stone chisels.{{cite journal |url=http://www.ramtops.co.uk/copper.html |title=The State of Our Knowledge About Ancient Copper Mining in Michigan |journal=The Michigan Archaeologist |volume=41 |issue=2–3 |pages=119–138 |year=1995 |first=Susan R. |last=Martin |url-status=dead |archive-url=https://web.archive.org/web/20160207073036/http://www.ramtops.co.uk/copper.html |archive-date=2016-02-07}}

The Keweenaw's rich deposits of copper (and some silver) were extracted on an industrial scale beginning around the middle of the 19th century. The industry grew through the latter part of the century and employed thousands of people well into the 20th century. Hard rock mining in the region ceased in 1967 though copper sulfide deposits continued for some time after in Ontonagon. This vigorous industry created a need for educated mining professionals and directly led in 1885 to the founding of the Michigan Mining School (now Michigan Technological University) in Houghton. Although MTU discontinued its undergraduate mining engineering program in 2006, the university continues to offer engineering degrees in a variety of other disciplines. (In 2012 mining engineering was restarted in the re-formed Department of Geological and Mining Engineering and Sciences.)

File:Keweenaw Forest.jpg

Running concurrently with the mining boom in the Keweenaw was the white pine lumber boom. Trees were cut for timbers for mine shafts, to heat the communities around the large copper mines, and to help build a growing nation. Much of the logging at the time was done in winter due to the ease of operability with the snow. Due to the logging practices at that time, the forest of the Keweenaw looks much different today from 100 years ago.

US 41 terminates in the northern Keweenaw at the Michigan State Park housing Fort Wilkins. US 41 was the so-called "Military Trail" that started in Chicago in the 1900s and ended in the Keweenaw wilderness. The restored fort has numerous exhibits.

For detailed information on the region's mineralogical history, see the virtual tour of the peninsula written by the Mineralogical Society of America, found in "External links" on this page. Information on the geological formations of the region are also detailed.

From 1964 to 1971, the University of Michigan and Michigan Technological University cooperated with NASA and the U.S. Navy to run the Keweenaw Rocket launch site.

A partial list of towns in the Keweenaw Peninsula:

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• Ahmeek
• Albion
• Allouez
• Atlantic Mine
• Baltic
• Bete Grise
• Blue Jacket
• Boot Jack Point
• Bumbletown
• Calumet
• Centennial
• Centennial Heights
• Central Mine
• Chassell
• Chickensville
• Clifton
• Copper Falls
• Copper Harbor
• Craig
• Delaware
• Dodgeville
• Dollar Bay
• Dreamland
• Eagle Harbor
• Eagle River
• Florida location
• Freda

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• Gay
• Gratiot location
• Gregoryville
• Hancock
• Hecla Location
• Henwood
• Houghton
• Hubbell
• Hurontown
• Jacobsville
• Kearsarge
• Lac La Belle
• Lake Linden
• Lake Medora
• Laurium
• Linwood
• Little Betsy
• Mandan
• Mason
• Mellonsville
• Mohawk
• Misery Bay

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• Ojibway
• Old Victoria
• Osceola
• Painesdale
• Pelkie
• Phillipsville
• Phoenix
• Pryor's Location
• Quincy
• Rabbit Bay
• Raymbaultown Location
• Red Jacket
• Redridge
• Ripley
• Seeberville
• Seneca location
• Senter
• South Kearsarge location
• South Range
• Swedetown
• Tamarack
• Tapiola
• Tecumseh
• Toivola
• Trimountain
• West Tamarack
• White City
• Wyoming location (Helltown)
• Yellow Jacket

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• Copper mining in Michigan
• Keweenaw National Historical Park
• Leelanau Peninsula
• Thimbleberry
• The Thumb

{{Reflist|2}}

• {{cite news |first1=Jim |last1=Harrison |author-link1=Jim Harrison |title=Imprint: My Upper Peninsula |url=https://www.nytimes.com/2013/12/01/travel/my-upper-peninsula.html?smid=pl-share |newspaper=The New York Times |date=November 30, 2013 |access-date=November 30, 2013}}
• {{cite book |last=Krause |first=David J. |title=The Making of a Mining District: Keweenaw Native Copper 1500-1870 |year=1992 |location=Detroit |publisher=Wayne State University Press |isbn=0-8143-2406-1}}.
• {{cite book |last=Lankton |first=Larry |title=Hollowed Ground: Copper Mining and Community Building on Lake Superior, 1840s-1990s |location=Detroit |publisher=Wayne State University Press |year=2010 |isbn=978-0-8143-3458-4}}, focuses on three companies, Calumet & Hecla, Copper Range, and Quincy, in a study of native copper mining and copper-sulfide mining on Upper Michigan's Keweenaw Peninsula.
• {{cite book |last=Thurner |first=Arthur W. |title=Strangers and Sojourners: A History of Michigan's Keweenaw Peninsula |location=Detroit |publisher=Wayne State University Press |year=1994 |isbn=0-8143-2396-0}}.

;Primary sources

• {{cite book |url=https://archive.org/details/bub_gb_6c0QAAAAIAAJ |quote=Bela Hubbard. |last1=Burt |first1=Williams A. |name-list-style=amp |last2=Hubbard |first2=Bela |title=Reports on the Mineral Region of Lake Superior |location=Buffalo |publisher=L. Danforth |year=1846}}.

{{Commons}}

• [http://www.keweenaw.info/ Keweenaw Convention & Visitors Bureau]
• [http://www.keweenaw.org/ Keweenaw Peninsula Chamber of Commerce]
• [http://www.keweenawhistory.com Keweenaw Time Traveler]
• [https://web.archive.org/web/20070205005041/http://www.coppercountryexplorer.com/ Copper Country Explorer]

{{Upper Peninsula of Michigan |state=expanded}}

{{Michigan}}

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Category:Copper mines in Michigan

Category:Peninsulas of Michigan

Category:Regions of Michigan

Category:Upper Peninsula of Michigan

Category:Landforms of Houghton County, Michigan

Category:Landforms of Keweenaw County, Michigan

Category:Geography of Houghton County, Michigan

Category:Geography of Keweenaw County, Michigan

Category:Volcanism of Michigan

Category:Rift volcanism

Category:Extinct volcanism