Ogemaw County area

Ogemaw County, Michigan covers 574.9 square miles: 563.5 square miles of land and 11.4 square miles of water. Its county seat is West Branch. An estimated 21,121 people lived there in 2025.

Official Census measurements · GEOID 261292026 Gazetteer · retrieved September 27, 2026
Land area563.5 mi²
Water area11.4 mi²
Population (2025)21,121
People per mi²37

County outline

Generalized outline of Ogemaw County, Michigan
2025 Census cartographic boundary, fitted to this frame. County maps are not at a common scale. The 2026 area measurements below come from the separate Gazetteer release. Map source and limitations.

Where Ogemaw County is located

Ogemaw County highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 98% of Ogemaw County’s measured area and water for 2%. Its combined area converts to 1,489.1 square kilometers or approximately 367,967 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land563.5061,459.474360,643.8
Water11.44229.6357,322.9
Total574.9481,489.108367,966.7

How Ogemaw County compares

By original Census land area, Ogemaw County ranks #52 of 83 in Michigan and #1829 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.992 times the Michigan county-equivalent median of 567.8 square miles. It accounts for 1% of the combined county land area in the state.

See the complete Michigan ranking · What counts as a county equivalent?

Population and density of Ogemaw County

The Census Bureau estimates that 21,121 people lived in Ogemaw County on July 1, 2025. That ranks #1,828 of 3,222 county equivalents nationally and #64 of 83 in Michigan. Since the April 1, 2020 estimates base of 20,769, the population has grown by 352 (+1.7%), compared with +0.5% for Michigan as a whole.

With 563.5 square miles of land, that is 37 people per square mile (14 per km²), placing Ogemaw County #1,814 nationally for density and #60 in Michigan. The median county equivalent has 47 people per square mile; the Michigan median is 62. Put another way, there are about 17 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate20,78120,78520,88421,03321,04221,121
Change—+4+99+149+9+79

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 Ogemaw County

Ogemaw County is divided into 16 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 Mills township, with 4,054 residents (19.2% of the county). The largest by land is Foster township, at 89.2 mi², or 15.8% of the county’s land. The county seat, West Branch township, has 2,607 residents. Among those with at least 1,000 residents in 2020, West Branch township grew fastest since then (+1.9%).

County subdivisionPopulation 2025Since 2020Land mi²Share of county land
Mills township4,054+1.8%34.26.1%
West Branch townshipCounty seat2,607+1.9%346%
West Branch cityCounty seat2,370+1.2%1.5390.3%
Churchill township1,569+1.7%35.56.3%
Edwards township1,396+1.6%34.96.2%
Hill township1,273+1.7%32.55.8%
Rose township1,257+1.5%52.89.4%
Ogemaw township1,175+1.6%36.36.4%
Horton township933+2.4%35.56.3%
Richland township834+1.8%34.86.2%
Foster township797+1.7%89.215.8%
Cumming township733+1.5%34.56.1%
Logan township599+1.9%35.26.3%
Klacking township586+2.3%35.96.4%
Rose City city581+1.4%1.0770.2%
Show the other 1 subdivisions
NamePopulation 2025Since 2020Land mi²
Goodar township357+2%35.4

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Ogemaw County. Land: 2026 Census Gazetteer. How communities are listed.

Metropolitan area

Ogemaw 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

9 ZIP Code Tabulation Areas have land in Ogemaw County; 4 of them have most of their land inside the county, and the others mainly cover neighboring areas.

486104862448635486544866148739487564876148770

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 Ogemaw County

Ogemaw County shares a land border with 5 county equivalents. It has more land than 4 of them. The largest neighbor is Oscoda County (565.7 mi²) and the smallest is Arenac County (363.2 mi²). Together with its neighbors, Ogemaw County forms a block of 3,063.5 mi² of land, of which it holds 18.4%.

Map of Ogemaw County and the 5 county equivalents that border it Iosco County, Michigan: 549.5 mi² landRoscommon County, Michigan: 519.9 mi² landOscoda County, Michigan: 565.7 mi² landArenac County, Michigan: 363.2 mi² landGladwin County, Michigan: 501.8 mi² land
Ogemaw County (dark) and its bordering county equivalents. Select a neighbor to open its profile. Drawn from the 2025 Census cartographic boundaries in an equal-area projection. How borders are determined.
Bordering county equivalentLand mi²Size vs. OgemawCompare
Oscoda County565.7about the sameCompare
Iosco County549.5about the sameCompare
Roscommon County519.91.1× smallerCompare
Gladwin County501.81.1× smallerCompare
Arenac County363.21.6× smallerCompare

How big is Ogemaw County compared with U.S. states?

Ogemaw County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.8 times as much. Michigan’s county land could hold about 100 areas the size of Ogemaw County.

Land area: Ogemaw County and the closest-sized states
Ogemaw County563.5 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 23.7 miles (38.2 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 Ogemaw County?

Ogemaw County has more land than 1,393 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Ogemaw County563.5 mi²
Michigan median567.8 mi²
National median604.5 mi²

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 Ogemaw County at #1,881 nationally by total area, 52 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.

Its water share is 2%, compared with a national county-equivalent median of 1.2% — 0.8 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 Ogemaw County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#1828Ottawa County, Michigan563.5Compare
#1829Ogemaw County, Michigan563.5This county
#1830Limestone County, Alabama563.4Compare

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 44.333280, -84.128073. 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: 1,459,473,467 m²; AWATER: 29,634,440 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.

Download the official county source ZIP ↗ · Methodology

Common questions

How big is Ogemaw County?

Ogemaw County, Michigan has 563.5 square miles (1,459.5 km²) of land and 11.4 square miles of water, for a total area of 574.9 square miles. It ranks #1829 of 3,222 U.S. county equivalents by land area.

Is Ogemaw County the largest county in Michigan?

No. Ogemaw County ranks #52 of 83 in Michigan by land area. The largest is Marquette County, with 1,809.1 square miles of land.

What counties border Ogemaw County?

Ogemaw County shares a land border with Iosco County, Roscommon County, Oscoda County, Arenac County, and Gladwin County.

What is the population of Ogemaw County?

The Census Bureau estimates Ogemaw County had 21,121 residents on July 1, 2025, ranking #1,828 of 3,222 county equivalents. That is 37 people per square mile of land.

What is the county seat of Ogemaw County?

The county seat of Ogemaw County is West Branch.

What cities and towns are in Ogemaw County?

Ogemaw County has 16 county subdivisions (cities, towns and townships). The most populous five are Mills township, West Branch township, West Branch city, Churchill township, and Edwards township.

Is Ogemaw County part of a metropolitan area?

No. Ogemaw County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.

How many ZIP codes are in Ogemaw County?

9 ZIP Code Tabulation Areas have land in Ogemaw County, and 4 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Ogemaw County compare with U.S. states?

It has less land than every state. Rhode Island, the smallest, has 1.8 times as much land.

How many acres of land are in Ogemaw County?

The land measurement converts to approximately 360,644 acres. Including water, total area is approximately 367,967 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.

Cite this county

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