County outline
Where Arenac County is located
Area breakdown
Land accounts for 53.4% of Arenac County’s measured area and water for 46.6%. Its combined area converts to 1,762.9 square kilometers or approximately 435,632 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 363.178 | 940.627 | 232,433.9 |
| Water | 317.497 | 822.313 | 203,198.1 |
| Total | 680.675 | 1,762.94 | 435,632 |
How Arenac County compares
By original Census land area, Arenac County ranks #81 of 83 in Michigan and #2645 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.64 times the Michigan county-equivalent median of 567.8 square miles. It accounts for 0.6% of the combined county land area in the state.
See the complete Michigan ranking · What counts as a county equivalent?
Population and density of Arenac County
The Census Bureau estimates that 15,068 people lived in Arenac County on July 1, 2025. That ranks #2,161 of 3,222 county equivalents nationally and #68 of 83 in Michigan. Since the April 1, 2020 estimates base of 14,999, the population has grown by 69 (+0.5%), compared with +0.5% for Michigan as a whole.
With 363.2 square miles of land, that is 41 people per square mile (16 per km²), placing Arenac County #1,720 nationally for density and #57 in Michigan. The median county equivalent has 47 people per square mile; the Michigan median is 62. Put another way, there are about 15 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 14,998 | 15,012 | 15,100 | 15,131 | 15,059 | 15,068 |
| Change | — | +14 | +88 | +31 | −72 | +9 |
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 Arenac County
Arenac County is divided into 15 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 Deep River township, with 2,076 residents (13.8% of the county). The largest by land is Arenac township, at 35.8 mi², or 9.9% of the county’s land. The county seat, Standish township, has 1,694 residents. Among those with at least 1,000 residents in 2020, Clayton township grew fastest since then (+1.3%).
| County subdivision | Population 2025 | Since 2020 | Land mi² | Share of county land |
|---|---|---|---|---|
| Deep River township | 2,076 | +1.2% | 35.3 | 9.7% |
| Standish townshipCounty seat | 1,694 | +0.7% | 27.6 | 7.6% |
| Standish cityCounty seat | 1,449 | −0.8% | 2.178 | 0.6% |
| Moffatt township | 1,170 | +0.6% | 31.5 | 8.7% |
| Clayton township | 1,014 | +1.3% | 32.1 | 8.8% |
| Sims township | 983 | +0.1% | 11.5 | 3.2% |
| Au Gres city | 954 | +0.7% | 2.278 | 0.6% |
| Lincoln township | 952 | +0.5% | 21 | 5.8% |
| Whitney township | 913 | +0.8% | 30.7 | 8.5% |
| Au Gres township | 892 | −0.9% | 33.3 | 9.2% |
| Arenac township | 869 | +0.3% | 35.8 | 9.9% |
| Mason township | 755 | +1.1% | 32.1 | 8.8% |
| Adams township | 549 | −0.7% | 35.6 | 9.8% |
| Turner township | 517 | +0.2% | 31.1 | 8.6% |
| Omer city | 281 | +1.8% | 1.132 | 0.3% |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Arenac County. Land: 2026 Census Gazetteer. How communities are listed.
Metropolitan area
Arenac 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
10 ZIP Code Tabulation Areas have land in Arenac County; 6 of them have most of their land inside the county, and the others mainly cover neighboring areas.
48610486504865848659487034874948756487634876548766
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 Arenac County
Arenac County shares a land border with 4 county equivalents. Each of them has more land than Arenac County. The largest neighbor is Ogemaw County (563.5 mi²) and the smallest is Bay County (442.4 mi²). Together with its neighbors, Arenac County forms a block of 2,420.4 mi² of land, of which it holds 15%.
| Bordering county equivalent | Land mi² | Size vs. Arenac | Compare |
|---|---|---|---|
| Ogemaw County | 563.5 | 1.6× larger | Compare |
| Iosco County | 549.5 | 1.5× larger | Compare |
| Gladwin County | 501.8 | 1.4× larger | Compare |
| Bay County | 442.4 | 1.2× larger | Compare |
How big is Arenac County compared with U.S. states?
Arenac County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.8 times as much. Michigan’s county land could hold about 156 areas the size of Arenac County.
Another way to picture it: the same land area would fill a square about 19.1 miles (30.7 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 Arenac County?
Arenac County has more land than 577 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 Arenac County at #1,491 nationally by total area, 1,154 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 46.6%, compared with a national county-equivalent median of 1.2% — 45.5 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 Arenac County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2644 | Toombs County, Georgia | 364 | Compare |
| #2645 | Arenac County, Michigan | 363.2 | This county |
| #2646 | DeKalb County, Indiana | 362.8 | 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 44.036833, -83.740675. 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: 940,627,671 m²; AWATER: 822,313,347 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 Arenac County?
Arenac County, Michigan has 363.2 square miles (940.6 km²) of land and 317.5 square miles of water, for a total area of 680.7 square miles. It ranks #2645 of 3,222 U.S. county equivalents by land area.
Is Arenac County the largest county in Michigan?
No. Arenac County ranks #81 of 83 in Michigan by land area. The largest is Marquette County, with 1,809.1 square miles of land.
What counties border Arenac County?
Arenac County shares a land border with Bay County, Iosco County, Ogemaw County, and Gladwin County.
What is the population of Arenac County?
The Census Bureau estimates Arenac County had 15,068 residents on July 1, 2025, ranking #2,161 of 3,222 county equivalents. That is 41 people per square mile of land.
What is the county seat of Arenac County?
The county seat of Arenac County is Standish.
What cities and towns are in Arenac County?
Arenac County has 15 county subdivisions (cities, towns and townships). The most populous five are Deep River township, Standish township, Standish city, Moffatt township, and Clayton township.
Is Arenac County part of a metropolitan area?
No. Arenac County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Arenac County?
10 ZIP Code Tabulation Areas have land in Arenac County, and 6 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Arenac County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 2.8 times as much land.
How many acres of land are in Arenac County?
The land measurement converts to approximately 232,434 acres. Including water, total area is approximately 435,632 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.