County outline
Where Alcona County is located
Area breakdown
Land accounts for 37.7% of Alcona County’s measured area and water for 62.3%. Its combined area converts to 4,637.8 square kilometers or approximately 1,146,014 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 674.655 | 1,747.348 | 431,779.2 |
| Water | 1,115.992 | 2,890.406 | 714,234.9 |
| Total | 1,790.647 | 4,637.754 | 1,146,014.1 |
How Alcona County compares
By original Census land area, Alcona County ranks #30 of 83 in Michigan and #1397 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.188 times the Michigan county-equivalent median of 567.8 square miles. It accounts for 1.2% of the combined county land area in the state.
See the complete Michigan ranking · What counts as a county equivalent?
Population and density of Alcona County
The Census Bureau estimates that 10,556 people lived in Alcona County on July 1, 2025. That ranks #2,447 of 3,222 county equivalents nationally and #75 of 83 in Michigan. Since the April 1, 2020 estimates base of 10,161, the population has grown by 395 (+3.9%), compared with +0.5% for Michigan as a whole.
With 674.7 square miles of land, that is 16 people per square mile (6 per km²), placing Alcona County #2,452 nationally for density and #73 in Michigan. The median county equivalent has 47 people per square mile; the Michigan median is 62. Put another way, there are about 41 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 10,184 | 10,290 | 10,382 | 10,502 | 10,551 | 10,556 |
| Change | — | +106 | +92 | +120 | +49 | +5 |
U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.
Cities and towns in Alcona County
Alcona County is divided into 12 municipalities and townships. In Michigan, county subdivisions are local governments, and together they cover all of the county’s land and residents.
The most populous is Harrisville township, with 1,355 residents (12.8% of the county). The largest by land is Mitchell township, at 142.6 mi², or 21.1% of the county’s land. Among those with at least 1,000 residents in 2020, Curtis township grew fastest since then (+4.7%).
| County subdivision | Population 2025 | Since 2020 | Land mi² | Share of county land |
|---|---|---|---|---|
| Harrisville townshipCounty seat | 1,355 | +3.8% | 30.3 | 4.5% |
| Greenbush township | 1,317 | +3.6% | 24.9 | 3.7% |
| Curtis township | 1,145 | +4.7% | 68.4 | 10.1% |
| Hawes township | 1,111 | +3.9% | 70 | 10.4% |
| Caledonia township | 1,071 | +3.6% | 67.6 | 10% |
| Alcona township | 999 | +3.5% | 57.5 | 8.5% |
| Mikado township | 891 | +4.3% | 71.3 | 10.6% |
| Gustin township | 804 | +4.1% | 35.7 | 5.3% |
| Haynes township | 680 | +3.5% | 34.9 | 5.2% |
| Harrisville cityCounty seat | 443 | +2.8% | 0.632 | 0.1% |
| Millen township | 374 | +4.5% | 70.8 | 10.5% |
| Mitchell township | 366 | +4.3% | 142.6 | 21.1% |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Alcona County. Land: 2026 Census Gazetteer. How communities are listed.
Metropolitan area
Alcona County is not part of any metropolitan or micropolitan statistical area in the Office of Management and Budget’s July 2023 delineation; 1,306 other county equivalents are also outside one. These areas are built around an urban core of at least 10,000 people plus the counties tied to it by commuting, so counties outside them are generally rural.
ZIP codes
13 ZIP Code Tabulation Areas have land in Alcona County; 10 of them have most of their land inside the county, and the others mainly cover neighboring areas.
48647487054872148728487374873848740487424874548750487614876249747
ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.
Counties bordering Alcona County
Alcona County shares a land border with 3 county equivalents. It has more land than every one of them. The largest neighbor is Alpena County (571.9 mi²) and the smallest is Iosco County (549.5 mi²). Together with its neighbors, Alcona County forms a block of 2,361.7 mi² of land, of which it holds 28.6%.
| Bordering county equivalent | Land mi² | Size vs. Alcona | Compare |
|---|---|---|---|
| Alpena County | 571.9 | 1.2× smaller | Compare |
| Oscoda County | 565.7 | 1.2× smaller | Compare |
| Iosco County | 549.5 | 1.2× smaller | Compare |
How big is Alcona County compared with U.S. states?
Alcona County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.5 times as much. Michigan’s county land could hold about 84 areas the size of Alcona County.
Another way to picture it: the same land area would fill a square about 26 miles (41.8 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.
State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.
What stands out about Alcona County?
Alcona County has more land than 1,825 of the other 3,221 county equivalents in the dataset.
A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.
Does including water change its rank?
Using land plus water places Alcona County at #373 nationally by total area, 1,024 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.
Its water share is 62.3%, compared with a national county-equivalent median of 1.2% — 61.2 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.
Closest positions in the national land ranking
These entries sit immediately beside Alcona County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1396 | New Madrid County, Missouri | 674.9 | Compare |
| #1397 | Alcona County, Michigan | 674.7 | This county |
| #1398 | Pope County, Minnesota | 674.6 | Compare |
Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.
Representative coordinates
The Census internal point is 44.657509, -83.294580. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 1,747,349,219 m²; AWATER: 2,890,404,965 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Alcona County?
Alcona County, Michigan has 674.7 square miles (1,747.3 km²) of land and 1,116 square miles of water, for a total area of 1,790.6 square miles. It ranks #1397 of 3,222 U.S. county equivalents by land area.
Is Alcona County the largest county in Michigan?
No. Alcona County ranks #30 of 83 in Michigan by land area. The largest is Marquette County, with 1,809.1 square miles of land.
What counties border Alcona County?
Alcona County shares a land border with Iosco County, Alpena County, and Oscoda County.
What is the population of Alcona County?
The Census Bureau estimates Alcona County had 10,556 residents on July 1, 2025, ranking #2,447 of 3,222 county equivalents. That is 16 people per square mile of land.
What is the county seat of Alcona County?
The county seat of Alcona County is Harrisville.
What cities and towns are in Alcona County?
Alcona County has 12 county subdivisions (cities, towns and townships). The most populous five are Harrisville township, Greenbush township, Curtis township, Hawes township, and Caledonia township.
Is Alcona County part of a metropolitan area?
No. Alcona County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Alcona County?
13 ZIP Code Tabulation Areas have land in Alcona County, and 10 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Alcona County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.5 times as much land.
How many acres of land are in Alcona County?
The land measurement converts to approximately 431,779 acres. Including water, total area is approximately 1,146,014 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.