The Keweenaw Peninsula (, ) is a

peninsula A peninsula is a landform that extends from a mainland and is only connected to land on one side. Peninsulas exist on each continent. The largest peninsula in the world is the Arabian Peninsula. Etymology The word ''peninsula'' derives , . T ...

of the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its so ...

Michigan Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ...

. Part of the greater landmass of the

Upper Peninsula The Upper Peninsula of Michigan—also known as Upper Michigan or colloquially the U.P. or Yoop—is the northern and more elevated of the two major landmasses that make up the U.S. state of Michigan; it is separated from the Lower Peninsula b ...

, the Keweenaw Peninsula projects about northeasterly into

Lake Superior Lake Superior is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. Lake Michigan–Huron has a larger combined surface area than Superior, but is normally considered tw ...

, forming Keweenaw Bay. The peninsula is part of Michigan's

Copper Country The Copper Country is an area in the Upper Peninsula of Michigan in the United States, including Keweenaw County, Michigan, Houghton, Baraga and Ontonagon counties as well as part of Marquette County. The area is so named as copper mining wa ...

region, as the region was home to the first major

copper mining Copper extraction is the multi-stage process of obtaining copper from list of copper ores, its ores. The conversion of copper ores consists of a series of physical, chemical, and electrochemical processes. Methods have evolved and vary with coun ...

boom in the United States. Copper mining was active in this region from the 1840s to the 1960s. The peninsula is bisected by the Keweenaw Waterway, a partly natural, partly artificial waterway serving as a canal. The north side of the canal is known locally as

Copper Island Copper Island is a local name given to the northern part of the Keweenaw Peninsula (projecting northeastward into Lake Superior at the western end of the Upper Peninsula of Michigan, United States of America), separated from the rest of the Kewe ...

. The cities of Houghton, the peninsula's largest population center, and Hancock, are located along the shores of the Keweenaw Waterway. Houghton is home to

Michigan Technological University Michigan Technological University (Michigan Tech, MTU, or simply Tech) is a public research university in Houghton, Michigan, United States. It was founded in 1885 as the Michigan Mining School, the first post-secondary institution in the Uppe ...

. The Keweenaw Peninsula is politically divided primarily between Houghton and

Keweenaw The Keweenaw Peninsula (, ) is a peninsula of the U.S. state of Michigan. Part of the greater landmass of the Upper Peninsula, the Keweenaw Peninsula projects about northeasterly into Lake Superior, forming Keweenaw Bay. The peninsula is part ...

counties, both of which occupy the Houghton micropolitan area. A small portion of the southeast of the peninsula is part of Baraga County.

Geology

The peninsula measures about in length and about in width at its base. The ancient

lava flow Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

s of the Keweenaw Peninsula were produced during the

Mesoproterozoic The Mesoproterozoic Era is a geologic era that occurred from . The Mesoproterozoic was the first era of Earth's history for which a fairly definitive geological record survives. Continents existed during the preceding era (the Paleoproterozoic ...

Era as a part of the

Midcontinent Rift The Midcontinent Rift System (MRS) or Keweenawan Rift is a long geological rift in the center of the North America, North American continent and south-central part of the North American plate. It formed when the continent's core, the North Ameri ...

between 1.096 and 1.087 billion years ago. This volcanic activity produced the only strata on Earth where large-scale economically recoverable 97 percent pure

native copper Native copper is an uncombined form of copper that occurs as a natural mineral. Copper is one of the few metallic elements to occur in native form, although it most commonly occurs in oxidized states and mixed with other elements. Native coppe ...

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 Breccia ( , ; ) is a rock composed of large angular broken fragments of minerals or Rock (geology), rocks cementation (geology), cemented together by a fine-grained matrix (geology), matrix. The word has its origins in the Italian language ...

as void or interclast fillings. The conglomerate layers occur as interbedded units within the volcanic pile. The Keweenaw Peninsula and

Isle Royale Isle Royale (, ) is an Islands of the Great Lakes, island of the Great Lakes located in the northwest of Lake Superior and part of the U.S. state of Michigan. The island and the 450 surrounding smaller islands and waters make up Isle Royale Na ...

, 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 Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

. These areas are also the unique location where

chlorastrolite Chlorastrolite, also known as Isle Royale Greenstone, is a green or bluish green stone.Arguably the rarest gemstone in the world and one of the most valuable American gemstones. The gem quality specimens are typically found on Isle Royale, a large ...

, the state gem of Michigan, can be found. The northern end of the peninsula is sometimes referred to as

(or ''"Kuparisaari"'' by Finnish immigrants), although this term is becoming less common. It is separated from the rest of the peninsula by the Keweenaw Waterway, a natural waterway which was dredged and expanded in the 1860s across the

between the cities of Houghton (named for Douglass Houghton) on the south side and Hancock on the north. A Keweenaw

Water Trail Water trails (also known as blueways) are marked routes on navigable waterway such as rivers, lakes, canals, and coastlines for recreational use. They allow access to waterways for non-motorized boats and sometimes motorized vessels, inner tube ...

has been established around Copper Island. The Water Trail stretches approximately and can be paddled in five to ten days, depending on weather and water conditions. 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.

Climate

Lake Superior significantly controls the climate of the Keweenaw Peninsula, keeping winters milder than those in surrounding areas. Spring is cool and brief, transitioning into a summer with highs near . Fall begins in September, with winter beginning in mid-November. The peninsula receives copious amounts of

lake-effect snow Lake-effect snow is produced during cooler atmospheric conditions when a cold air mass moves across long expanses of warmer lake water. The lower layer of air, heated by the lake water, picks up water vapor from the lake and rises through colde ...

from Lake Superior. Official records are maintained close to the base of the peninsula in

Hancock, Michigan Hancock is a city in the Upper Peninsula of Michigan, Upper Peninsula of the U.S. state of Michigan. The population of Hancock was 4,501 at the 2020 United States census. The city is located within Houghton County, Michigan, Houghton County, and ...

, where the annual snowfall average is about . Keweenaw County reports daily snowfall, and monthly and seasonal totals since 2006. In the Keweenaw community of

Delaware Delaware ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic and South Atlantic states, South Atlantic regions of the United States. It borders Maryland to its south and west, Pennsylvania to its north, New Jersey ...

, an unofficial record gives an average of about (1957-2011) and the record snowfall for one season of in 1979. Averages over certainly occur in the higher elevations closer to the tip of the peninsula.

History

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. 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

) 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.) Keweenaw Forest

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 The University of Michigan (U-M, U of M, or Michigan) is a public university, public research university in Ann Arbor, Michigan, United States. Founded in 1817, it is the oldest institution of higher education in the state. The University of Mi ...

and Michigan Technological University cooperated with

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

and the

U.S. Navy The United States Navy (USN) is the maritime service branch of the United States Department of Defense. It is the world's most powerful navy with the largest displacement, at 4.5 million tons in 2021. It has the world's largest aircraft ...

to run the Keweenaw Rocket launch site.

Communities

A partial list of towns in the Keweenaw Peninsula: * Ahmeek *Albion * Allouez * Atlantic Mine *

Baltic Baltic may refer to: Peoples and languages *Baltic languages, a subfamily of Indo-European languages, including Lithuanian, Latvian and extinct Old Prussian *Balts (or Baltic peoples), ethnic groups speaking the Baltic languages and/or originatin ...

* Bete Grise * Blue Jacket *Boot Jack Point * Bumbletown * Calumet *

Centennial A centennial, or centenary in British English, is a 100th anniversary or otherwise relates to a century. Notable events Notable centennial events at a national or world-level include: * Centennial Exhibition, 1876, Philadelphia, Pennsylvania. ...

* Centennial Heights * Central Mine * Chassell *Chickensville * Clifton * Copper Falls * Copper Harbor * Craig *

* Dodgeville * Dollar Bay * Dreamland * Eagle Harbor * Eagle River * Florida location * Freda * Gay * Gratiot location * Gregoryville * Hancock * Hecla Location *Henwood * Houghton * Hubbell * Hurontown * Jacobsville * Kearsarge * Lac La Belle * Lake Linden * Lake Medora *

Laurium Lavrio, Lavrion or Laurium (; (later ); from Middle Ages until 1908: Εργαστήρια ''Ergastiria'') is a town in southeastern part of Attica, Greece. It is part of Athens metropolitan area and the seat of the municipality of Lavreotik ...

*Linwood * Little Betsy *

Mandan The Mandan () are a Native American tribe of the Great Plains who have lived for centuries primarily in what is now North Dakota. They are enrolled in the Three Affiliated Tribes of the Fort Berthold Reservation. About half of the Mandan still ...

* Mason *Mellonsville * Mohawk * Misery Bay *

Ojibway The Ojibwe (; Ojibwe writing systems#Ojibwe syllabics, syll.: ᐅᒋᐺ; plural: ''Ojibweg'' ᐅᒋᐺᒃ) are an Anishinaabe people whose homeland (''Ojibwewaki'' ᐅᒋᐺᐘᑭ) covers much of the Great Lakes region and the Great Plains, n ...

* Old Victoria *

Osceola Osceola (1804 – January 30, 1838, Vsse Yvholv in Muscogee language, Creek, also spelled Asi-yahola), named Billy Powell at birth, was an influential leader of the Seminole people in Florida. His mother was Muscogee, and his great-grandfa ...

* 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 ''Larix laricina'', commonly known as the tamarack, hackmatack, eastern larch, black larch, red larch, or American larch, is a species of larch native to Canada, from eastern Yukon and Inuvik, Northwest Territories east to Newfoundland, and als ...

Tapiola Tapiola (; ) is a district of the municipality of Espoo on the south coast of Finland, and is one of the major urban centres of Espoo. It is located in the western part of Helsinki capital region. The name ''Tapiola'' is derived from ''Tapio (spi ...

*Tecumseh * Toivola * Trimountain * West Tamarack * White City * Wyoming location (Helltown) * Yellow Jacket

References

External links

Keweenaw Convention & Visitors BureauKeweenaw Peninsula Chamber of CommerceKeweenaw Time TravelerCopper Country Explorer
{{coord, 47, 12, 00, N, 88, 25, 30, W, display=title Copper mines in Michigan Peninsulas of Michigan Regions of Michigan Upper Peninsula of Michigan Landforms of Houghton County, Michigan Landforms of Keweenaw County, Michigan Geography of Houghton County, Michigan Geography of Keweenaw County, Michigan Volcanism of Michigan Rift volcanism Extinct volcanism