County outline
Where Mason County is located
Area breakdown
Land accounts for 39.8% of Mason County’s measured area and water for 60.2%. Its combined area converts to 3,217.6 square kilometers or approximately 795,082 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 494.969 | 1,281.964 | 316,780.2 |
| Water | 747.346 | 1,935.617 | 478,301.4 |
| Total | 1,242.315 | 3,217.581 | 795,081.6 |
How Mason County compares
By original Census land area, Mason County ranks #73 of 83 in Michigan and #2104 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.872 times the Michigan county-equivalent median of 567.8 square miles. It accounts for 0.9% of the combined county land area in the state.
See the complete Michigan ranking · What counts as a county equivalent?
Population and density of Mason County
The Census Bureau estimates that 29,040 people lived in Mason County on July 1, 2025. That ranks #1,517 of 3,222 county equivalents nationally and #49 of 83 in Michigan. Since the April 1, 2020 estimates base of 29,059, the population has declined by 19 (−0.1%), compared with +0.5% for Michigan as a whole.
With 495 square miles of land, that is 59 people per square mile (23 per km²), placing Mason County #1,404 nationally for density and #44 in Michigan. The median county equivalent has 47 people per square mile; the Michigan median is 62. Put another way, there are about 11 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 29,033 | 29,344 | 29,341 | 29,144 | 29,063 | 29,040 |
| Change | — | +311 | −3 | −197 | −81 | −23 |
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 Mason County
Mason County is divided into 17 municipalities and townships. In Michigan, county subdivisions are local governments, and together they cover all of the county’s land and residents; a few are unorganized areas without their own government.
The most populous is Ludington city, with 7,634 residents (26.3% of the county). The largest by land is Grant township, at 48.7 mi², or 9.8% of the county’s land. Among those with at least 1,000 residents in 2020, Sheridan township grew fastest since then (+0.8%).
| County subdivision | Population 2025 | Since 2020 | Land mi² | Share of county land |
|---|---|---|---|---|
| Ludington cityCounty seat | 7,634 | −0.8% | 3.36 | 0.7% |
| Hamlin township | 3,732 | +0.6% | 27.4 | 5.5% |
| Amber township | 2,550 | +0.7% | 27.6 | 5.6% |
| Pere Marquette charter township | 2,371 | −0.5% | 14.1 | 2.8% |
| Victory township | 1,415 | +0.6% | 35.9 | 7.3% |
| Branch township | 1,413 | +0.6% | 35.4 | 7.2% |
| Scottville city | 1,348 | −0.8% | 1.49 | 0.3% |
| Custer township | 1,313 | −0.3% | 34.9 | 7.1% |
| Riverton township | 1,232 | −0.3% | 35.2 | 7.1% |
| Sherman township | 1,128 | −0.1% | 36.2 | 7.3% |
| Sheridan township | 1,048 | +0.8% | 34.3 | 6.9% |
| Summit township | 992 | +0.1% | 12.8 | 2.6% |
| Grant township | 925 | +0.1% | 48.7 | 9.8% |
| Free Soil township | 841 | +0.2% | 38.6 | 7.8% |
| Eden township | 585 | −0.3% | 35.4 | 7.2% |
Show the other 2 subdivisions
| Name | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Logan township | 334 | +1.2% | 36.1 |
| Meade township | 179 | 0% | 37.4 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Mason County. Land: 2026 Census Gazetteer. How communities are listed.
Metropolitan area
Mason County is a central county of the Ludington, MI Micropolitan Statistical Area. Mason County is the area’s only county equivalent, so the micro area has the same 495 square miles of land. By combined land it ranks #438 of 542 micropolitan areas, and #448 by population.
ZIP codes
10 ZIP Code Tabulation Areas have land in Mason County; 6 of them have most of their land inside the county, and the others mainly cover neighboring areas.
49402494054941049411494314944949454494584964449660
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 Mason County
Mason County shares a land border with 3 county equivalents. Each of them has more land than Mason County. The largest neighbor is Lake County (567.6 mi²) and the smallest is Oceana County (538.1 mi²). Together with its neighbors, Mason County forms a block of 2,143 mi² of land, of which it holds 23.1%.
| Bordering county equivalent | Land mi² | Size vs. Mason | Compare |
|---|---|---|---|
| Lake County | 567.6 | 1.1× larger | Compare |
| Manistee County | 542.3 | 1.1× larger | Compare |
| Oceana County | 538.1 | 1.1× larger | Compare |
How big is Mason County compared with U.S. states?
Mason County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.1 times as much. Michigan’s county land could hold about 114 areas the size of Mason County.
Another way to picture it: the same land area would fill a square about 22.2 miles (35.8 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 Mason County?
Mason County has more land than 1,118 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 Mason County at #565 nationally by total area, 1,539 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 60.2%, compared with a national county-equivalent median of 1.2% — 59 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 Mason County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2103 | White County, Illinois | 495 | Compare |
| #2104 | Mason County, Michigan | 495 | This county |
| #2105 | Jasper County, Illinois | 494.6 | 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 43.957196, -86.442937. 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: 1,281,963,197 m²; AWATER: 1,935,616,629 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 Mason County?
Mason County, Michigan has 495 square miles (1,282 km²) of land and 747.3 square miles of water, for a total area of 1,242.3 square miles. It ranks #2104 of 3,222 U.S. county equivalents by land area.
Is Mason County the largest county in Michigan?
No. Mason County ranks #73 of 83 in Michigan by land area. The largest is Marquette County, with 1,809.1 square miles of land.
What counties border Mason County?
Mason County shares a land border with Lake County, Oceana County, and Manistee County.
What is the population of Mason County?
The Census Bureau estimates Mason County had 29,040 residents on July 1, 2025, ranking #1,517 of 3,222 county equivalents. That is 59 people per square mile of land.
What is the county seat of Mason County?
The county seat of Mason County is Ludington.
What cities and towns are in Mason County?
Mason County has 17 county subdivisions (cities, towns and townships). The most populous five are Ludington city, Hamlin township, Amber township, Pere Marquette charter township, and Victory township.
Is Mason County part of a metropolitan area?
Yes. It is a central county of the Ludington, MI Micropolitan Statistical Area.
How many ZIP codes are in Mason County?
10 ZIP Code Tabulation Areas have land in Mason 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 Mason County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 2.1 times as much land.
How many acres of land are in Mason County?
The land measurement converts to approximately 316,780 acres. Including water, total area is approximately 795,082 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.