County Maps US

Marshall County, Indiana

A county in Indiana, ranked 32 of 92 by population.

CountyFIPS 18099

Within Indiana
Marshall County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data. The dot marks Plymouth, the county seat, located via the 2025 Census Gazetteer.

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Population
46,599
+535 (+1.2%) since 2020
Land area
443.6
square miles. A further 1.4% of the total area is water
Population density
105
people per square mile, computed rather than published
County seat
Plymouth
Seat of county government.
Established
1835
190 years ago
Largest city
Plymouth city
Population 11,081.

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Satellite view

Aerial imagery of Marshall County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Marshall County, Indiana from the USGS National Map, with its boundary outlined
Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 800 by 795 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Marshall County ranks

Position among the 92 counties of Indiana, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn IndianaNationally
Population46,59932nd of 921,060th of 3,144
Land area443.6 sq mi24th of 922,291st of 3,144
Population density105 per sq mi38th of 92867th of 3,144
Median household income$71,80832nd of 921,062nd of 3,143

Full data for Marshall County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population46,599Vintage 2025 Population Estimates
Population in 202046,064Vintage 2025 Population Estimates
2020 estimates base?46,079Vintage 2025 Population Estimates
Land area443.6 sq mi2025 Gazetteer Files
Water area6.1 sq mi2025 Gazetteer Files
Total area449.7 sq mi2025 Gazetteer Files
Population density?105 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$71,808American Community Survey 2020-2024 5-Year Estimates
Median home value$204,900American Community Survey 2020-2024 5-Year Estimates
Median age39.8American Community Survey 2020-2024 5-Year Estimates
Households17,758American Community Survey 2020-2024 5-Year Estimates
Housing units20,111American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths
+23
562 births, 539 deaths
Net migration
+36
More people moved in than moved out.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 6 areas bordering Marshall County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering areaStateShared borderPopulation
St. Joseph CountyIndiana24 mi272,861
Fulton CountyIndiana20 mi20,091
Kosciusko CountyIndiana19 mi80,892
Starke CountyIndiana18 mi23,425
Elkhart CountyIndiana3.0 mi208,774
Pulaski CountyIndianaa single point12,463

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

All 92 counties of Indiana

Open the interactive Indiana county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.