Keweenaw County is a county in Michigan, United States, occupying the northeastern tip of the Keweenaw Peninsula and Isle Royale out in Lake Superior. It had a population of 2,046 at the 2020 census and covers 5,966 square miles (15,450 km2) — almost all of it open water — centred near 47°29′N 88°10′W.
Eagle River is the county seat, and its postal code is 49950. The county holds one incorporated village, four census-designated places and about a dozen unincorporated mining communities, grouped into five civil townships. Keweenaw sits in the Eastern time zone and carries FIPS code 26083.
Towns & Villages in Keweenaw County
Keweenaw County has roughly a dozen named settlements, most of them former copper-mining locations that never grew large enough to incorporate. Ahmeek is the only village; Copper Harbor, Eagle Harbor, Eagle River and Fulton are census-designated places (CDPs); everything else on the list below is an unincorporated community, some now reduced to a handful of houses.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Ahmeek | Village | 129 | 49901 |
| Eagle River | CDP · seat | — | 49950 |
| Copper Harbor | CDP | — | 49918 |
| Eagle Harbor | CDP | — | 49950 |
| Fulton | CDP | — | 49950 |
| Mohawk | Unincorp. | — | 49950 |
| Allouez | Unincorp. | — | 49805 |
| Central | Unincorp. | — | — |
| Phoenix | Unincorp. | — | — |
| Delaware | Unincorp. | — | — |
| Mandan | Unincorp. | — | — |
| Lac La Belle | Unincorp. | — | — |
| Bete Grise | Unincorp. | — | — |
| Windigo | Unincorp. (Isle Royale) | — | — |
Mohawk, Eagle Harbor and Fulton share Eagle River’s 49950 ZIP code rather than carrying their own, since the U.S. Postal Service routes them all through the same post office. Windigo, a National Park Service dock and ranger station, sits on Isle Royale itself — separated from the peninsula mainland by roughly 15 miles of open Lake Superior and reachable only by boat or seaplane.
Townships
Keweenaw County is divided into five civil townships. The Census Bureau does not publish separate 2020 population figures below the county level here, so populations are omitted below rather than estimated.
| Township | Pop. (2020) | Main settlements |
|---|---|---|
| Allouez Township | — | Ahmeek, Allouez, Mohawk |
| Eagle Harbor Township | — | Eagle Harbor, Eagle River, Central |
| Grant Township | — | Copper Harbor, Fort Wilkins |
| Houghton Township | — | Isle Royale (Windigo, Rock Harbor) |
| Sherman Township | — | Lac La Belle, Bete Grise, Delaware |
ZIP Codes
- 49950 — Mohawk (also serves Eagle River, Eagle Harbor and Fulton)
- 49901 — Ahmeek
- 49805 — Allouez
- 49918 — Copper Harbor
Smaller communities such as Central, Phoenix, Delaware, Mandan, Lac La Belle and Bete Grise have no ZIP code of their own and are served by one of the four post offices above.
Geography
Of all the counties in the United States, Keweenaw County has the highest share of water to total land — 91% of its 5,966 square miles is Lake Superior, stretching all the way to the state’s water border with Ontario and Minnesota. The remaining 540 square miles of dry land splits into two disconnected pieces: the rugged, forested tip of the Keweenaw Peninsula, and Isle Royale, an island wilderness roughly 15 miles offshore that is almost entirely federal parkland. The peninsula’s spine rises to Mount Horace Greeley (1,550 feet) and Mount Gratiot (1,490 feet), remnants of the same basalt ridge that made the area North America’s richest native-copper deposit.
Because Keweenaw’s mainland is a narrow peninsula and Isle Royale sits offshore, the county borders only one other county by land: Houghton County lies to the south, across the peninsula’s narrow neck.
Demographics
The 2020 census counted 2,046 residents, making Keweenaw the least populous county in Michigan. Ahmeek, the largest incorporated place, had 129 residents; Mohawk and Eagle Harbor are generally considered the largest unincorporated concentrations of year-round and seasonal housing. Median household income data at the county level is not verified here; Michigan’s statewide median household income is $69,183. With only 540 square miles of land, the county’s population density works out to roughly 3.8 people per square mile — among the lowest of any county east of the Mississippi.
Economy & Local Life
Keweenaw’s economy today runs on tourism, seasonal recreation and small-scale government and park employment, a sharp turn from its 19th-century identity as a copper-mining powerhouse. Keweenaw National Historical Park, headquartered at Calumet just south of the county line, has park units and historic mine sites within the county, and Isle Royale National Park — reachable by ferry from Copper Harbor or Houghton — draws backpackers and boaters each summer. Copper Harbor is a base for mountain biking and Lake Superior boating; the surrounding hills carry part of the Keweenaw’s growing network of trails. Winters bring heavy lake-effect snow, and the county is a destination for snowmobiling and cross-country skiing when most other Michigan roads have long since cleared.
History
Keweenaw County was organized on March 11, 1861, split off from Houghton County as copper mining pushed settlement to the peninsula’s tip. Its name comes from an Ojibwe word generally translated as “portage,” referencing the short overland route Native travelers and later voyageurs used to cross the peninsula rather than paddle around it. Between the 1840s and the 1960s, mines around Central, Phoenix, Delaware and Allouez produced native copper on an industrial scale, drawing Cornish, Finnish and French-Canadian immigrant labor and building towns that, in several cases, have since all but vanished. When the mines closed, the county’s population fell sharply, and much of its 20th-century history has been the transition from mining camp to a lightly populated recreation and conservation area anchored by two national parks.
Getting There
US 41 runs the length of the peninsula and terminates at Copper Harbor, the northern end of the highway that begins in Miami, Florida; M-26 branches off along the Lake Superior shoreline through Eagle River and Eagle Harbor.
- Houghton, Michigan — about 45 miles south
- Calumet, Michigan — about 25 miles south
- Marquette, Michigan — about 100 miles southeast
The nearest commercial airport is Houghton County Memorial Airport (CMX) in Hancock, with connecting flights to Chicago and Minneapolis. Isle Royale is reached only by ferry or seaplane from Copper Harbor, Houghton or Grand Portage, Minnesota — there is no road or bridge access.
Frequently Asked Questions
Where is Keweenaw County, Michigan?
It occupies the northeastern tip of the Upper Peninsula’s Keweenaw Peninsula, plus Isle Royale offshore in Lake Superior.
What is the population of Keweenaw County?
2,046 residents at the 2020 census, the smallest of any Michigan county.
How big is Keweenaw County?
5,966 square miles (15,450 km2) in total, but only 540 square miles is land — 91% is Lake Superior water.
What is the county seat of Keweenaw County?
Eagle River is the county seat.
How many towns are in Keweenaw County?
One village (Ahmeek), four census-designated places, and roughly a dozen smaller unincorporated communities.
What ZIP codes are in Keweenaw County?
49901 (Ahmeek), 49805 (Allouez), 49918 (Copper Harbor) and 49950 (Mohawk, Eagle River, Eagle Harbor, Fulton).
Does Keweenaw County include Isle Royale?
Yes. Isle Royale National Park, an island wilderness about 15 miles offshore in Lake Superior, is part of Keweenaw County even though it has no road connection to the peninsula.
More counties in this state: Towns and villages in Michigan.