Keweenaw Peninsula

Last updated
Keweenaw Peninsula KeweenawPeninsula.svg
Keweenaw Peninsula

The Keweenaw Peninsula ( /ˈkwɪnɔː/ KEE-wi-naw, sometimes locally /ˈkiːvənɔː/) is the northernmost part of Michigan's Upper Peninsula. It projects into Lake Superior and was the site of the first copper boom in the United States, leading to its moniker of "Copper Country." As of the 2000 census, its population was roughly 43,200. Its major industries are now logging and tourism, as well as jobs related to Michigan Technological University and Finlandia University.



Cross-section of the Lake Superior basin showing the tilted strata of volcanic rock that form both the Keweenaw Peninsula and Isle Royale 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
Lake Superior syncline USGS Lake Superior syncline.png
Lake Superior syncline

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. [1] 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. [2]

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 Indians were traded as far south as present-day Alabama. [3] These areas are also the unique location where chlorastrolite, the state gem of Michigan, can be found.

Copper Island MichiganCopperIsland.svg
Copper Island

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. [4] [5] It is separated from the rest of the peninsula by the Keweenaw Waterway, a natural waterway which was dredged and expanded in the 1860s [6] 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 125 miles (201 km) 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.


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

Lake Superior significantly controls the climate of the Keweenaw Peninsula, keeping winters milder than those in surrounding areas. [7] Spring is cool and brief, transitioning into a summer with highs near 70 °F (21 °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, [8] where the annual snowfall average is about 220 inches (560 cm). Farther north, in a community called Delaware, an unofficial average of about 240 inches (610 cm) is maintained. At Delaware, the record snowfall for one season was 390 inches (990 cm) in 1979. [9] Averages over 250 inches (640 cm) certainly occur in the higher elevations closer to the tip of the peninsula.


Spectacular copper and calcite specimen from the Pewabic Lode, Keweenaw Peninsula. Copper and calcite (Mesoproterozoic, 1.05-1.06 Ga; Pewabic Lode, Upper Peninsula of Michigan, USA) 3 (16679632374).jpg
Spectacular copper and calcite specimen from the Pewabic Lode, Keweenaw Peninsula.

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. [10]

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.)

Second-growth forest near the tip of the Keweenaw, facing west Keweenaw Forest.jpg
Second-growth forest near the tip of the Keweenaw, facing west

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:

See also

Related Research Articles

Upper Peninsula of Michigan Northern major peninsula of the U.S. state of Michigan

The Upper Peninsulaof Michigan – also known as Upper Michigan or colloquially the U.P. – 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 by the Straits of Mackinac. It is bounded primarily by Lake Superior to the north, separated from the Canadian province of Ontario at the east end by the St. Marys River, and flanked by Lake Huron and Lake Michigan along much of its south. Although the peninsula extends as a geographic feature into the state of Wisconsin, the state boundary follows the Montreal and Menominee rivers and a line connecting them.

Michigan Technological University Public research university in Houghton, Michigan

Michigan Technological University is a public research university in Houghton, Michigan. Its main campus sits on 925 acres (374 ha) on a bluff overlooking Portage Lake. Michigan Tech was founded in 1885 as the first post-secondary institution in the Upper Peninsula of Michigan and was created to train mining engineers to operate the local copper mines. Science, technology, forestry and business have been added to the numerous engineering disciplines, and Michigan Tech now offers more than 130 degree programs through its five colleges and schools. It is classified among "R2: Doctoral Universities – High research activity".

Houghton, Michigan City in Michigan, United States

Houghton is the largest city and county seat of Houghton County in the U.S. state of Michigan. Located on the Keweenaw Peninsula, Houghton is the largest city in the Copper Country region. It is the fifth largest city in the Upper Peninsula, with a population of 7,708 at the 2010 census. Houghton is the principal city of the Houghton micropolitan area, which includes all of Houghton and Keweenaw County.

Copper Island Northern part of the Keweenaw Peninsula in Michigan, United States

Copper Island is a local name given to the northern part of the Keweenaw Peninsula, separated from the rest of the Keweenaw Peninsula by Portage Lake and the Keweenaw Waterway.

Hancock, Michigan City in Michigan, United States

Hancock is a city in Houghton County in the U.S. state of Michigan. It is located across the Keweenaw Waterway from the city of Houghton on the Keweenaw Peninsula. The population was 4,634 at the 2010 census. The city has been consistently ranked as the third-snowiest city in the United States by The Weather Channel.

Keweenaw County, Michigan U.S. county in Michigan

Keweenaw County is a county in the Upper Peninsula of the U.S. state of Michigan, the state's northernmost county. As of the 2010 United States Census, the population was 2,156, making it Michigan's least populous county. It is also the state's largest county by total area, when the waters of Lake Superior are included in the total. The county seat is Eagle River.

Calumet Charter Township, Michigan Charter township in Michigan, United States

Calumet Charter Township is a charter township of Houghton County in the U.S. state of Michigan. The population was 6,489 at the 2010 census, down from 6,997 at the 2000 census. Even with a decreasing population, the township remains the largest township by population in Houghton County.

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 was prevalent there from 1845 until the late 1960s, with one mine continuing through 1995. In its heyday in the latter half of the 19th century and the early 20th century, the area was the world's greatest producer of copper.

Portage Lake Lift Bridge

The Portage Lake Lift Bridge connects the cities of Hancock and Houghton, in the US state of Michigan. It crosses Portage Lake, a portion of the waterway which cuts across the Keweenaw Peninsula with a canal linking the final several miles to Lake Superior to the northwest. US Highway 41 (US 41) and M-26 are both routed across the bridge. It is the only land-based link between the north and south sections of the Keweenaw peninsula.

Douglass Houghton

Douglass Houghton was an American geologist and physician, primarily known for his exploration of the Keweenaw Peninsula of Michigan. It was the site of a copper boom and extensive copper mining beginning in the 19th century. He was appointed in 1839 as the first state geologist of Michigan, after it was admitted to the union, and served in that position for the rest of his life.

Keweenaw Waterway

The Keweenaw Waterway is a partly natural, partly artificial waterway which cuts across the Keweenaw Peninsula of Michigan; it separates Copper Island from the mainland. Parts of the waterway are variously known as the Keweenaw Waterway, Portage Canal, Portage Lake Canal, Portage River, Lily Pond, Torch Lake, and Portage Lake. The waterway connects to Lake Superior at its north and south entries, with sections known as Portage Lake and Torch Lake in between. The primary tributary to Portage Lake is the Sturgeon River.

Native copper Mineral (as opposed to the chemical element)

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 copper was an important ore of copper in historic times and was used by pre-historic peoples.

Keweenaw National Historical Park U.S. national park in Michigan

Keweenaw National Historical Park is a unit of the U.S. National Park Service. Established in 1992, the park celebrates the life and history of the Keweenaw Peninsula in the Upper Peninsula of the U.S. state of Michigan. As of 2009, it is a partly privatized park made up of two primary units, the Calumet Unit and the Quincy Unit, and 21 cooperating "Heritage Sites" located on federal, state, and privately owned land in and around the Keweenaw Peninsula. The National Park Service owns approximately 1,700 acres (690 ha) in the Calumet and Quincy Units. Units are located in Baraga, Houghton, Keweenaw, and Ontonagon counties.

Charles Thomas Jackson

Charles Thomas Jackson was an American physician and scientist who was active in medicine, chemistry, mineralogy, and geology.

National Register of Historic Places listings in Keweenaw County, Michigan Wikimedia list article

The following is a list of Registered Historic Places in Keweenaw County, Michigan.

Freda, Michigan Unincorporated community in Michigan, United States

Freda is an unincorporated community fifteen miles west of Houghton, United States in the Stanton Township. Freda appears on the Beacon Hill U.S. Geological Survey Map. Freda was a key part of the copper industry in the Upper Peninsula of Michigan, on the western edge of the Keweenaw Peninsula. The large mill located in the town received copper ore from the surrounding region. The town was named after William A. Paine's daughter.

Midcontinent Rift System Geological rift in the center of the North American continent

The Midcontinent Rift System (MRS) or Keweenawan Rift is a 2,000 km (1,200 mi) long geological rift in the center of the North American continent and south-central part of the North American plate. It formed when the continent's core, the North American craton, began to split apart during the Mesoproterozoic era of the Precambrian, about 1.1 billion years ago. The rift failed, leaving behind thick layers of igneous rock that are exposed in its northern reaches, but buried beneath later sedimentary formations along most of its western and eastern arms. Those arms meet at Lake Superior, which is contained within the rift valley. The lake's north shore in Ontario and Minnesota defines the northern arc of the rift. From the lake, the rift's eastern arm trends south to central lower Michigan, and possibly into Indiana, Ohio, Kentucky, Tennessee, and Alabama. The western arm runs from Lake Superior southwest through portions of Wisconsin, Minnesota, Iowa, and Nebraska to northeastern Kansas, and possibly into Oklahoma.

Ontonagon Boulder

The Ontonagon Boulder is a 3,708 pounds (1,682 kg) boulder of native copper originally found in the Upper Peninsula of Michigan, United States, and now in the possession of the Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution. In 1843 the boulder was purchased from a local entrepreneur and shipped to Washington D.C.

Copper mining in Michigan

Copper mining in Michigan became an important industry in the 19th and early 20th centuries. Its rise marked the start of copper mining as a major industry in the United States.

Toivola, Michigan Unincorporated community in Michigan, United States

Toivola is an unincorporated community in Houghton County, Michigan, United States. The far-flung rural community is divided between Stanton Township, Adams Township, and Bohemia Township. It is found along M-26, 8 miles (13 km) southwest of South Range, 16 miles (25.7 km) from Houghton, and 35 miles (56 km) from Ontonagon. Toivola has a post office with ZIP code 49965. The community's historic industries include mainly agrarian uses and lumbering.


  1. "Geologic Timeline - Keweenaw National Historical Park (U.S. National Park Service)". Retrieved 2018-06-08.
  2. Huber, N. King (1973). "The Portage Lake Volcanics (Middle Keweenawan) on Isle Royale, Michigan". Geological Survey Professional Paper. Professional Paper. doi: 10.3133/pp754C . 754—C.
  3. Public Law 102-543 (Oct. 27, 1992); 106 STAT. 3569
  4. Holmio, Armas K. E.; Ryynanen, Ellen M. (2001). History of the Finns in Michigan. Wayne State University Press. p. 76. ISBN   978-0-8143-2974-0 . Retrieved 2008-09-28.
  5. "An Interior Ellis Island: Ethnic Diversity and the Peopling of Michigan's Copper Country, Keweenaw Ethnic Groups: The Finns". MTU Archives and Copper Country Historical Collection. J. Robert Van Pelt Library, Michigan Technological University. Archived from the original on 2007-03-08.
  6. "Houghton". Exploring the North.
  7. "Keweenaw". US National Park Serive. Retrieved 21 October 2011.
  8. "Snowfall Records". Michigan Technological University. Retrieved 21 October 2011.
  9. "Keweenaw Snowfall Record". Eagle Harbor Web. Retrieved 21 October 2011.
  10. Martin, Susan R. (1995). "The State of Our Knowledge About Ancient Copper Mining in Michigan". The Michigan Archaeologist. 41 (2–3): 119–138. Archived from the original on 2016-02-07.

Further reading

Primary sources

Coordinates: 47°15′N88°20′W / 47.250°N 88.333°W / 47.250; -88.333