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Marshall County, IA Demographics

Marshall County, IA is the 15th most populous of 99 counties in Iowa, with 40,105 residents across 573 square miles. That is about 70 people per square mile.

At the 2020 census

Population 40,105
Land area 573 sq mi
Density 70 / sq mi

Data: 2020 Census · American Community Survey 2024

How Marshall County compares to the US

We're computing this county's comparison table — check back shortly. Population, land area, and density above are already exact.

Central Location: Marshall County, IA

Measured from the county's main population center using 2020 census blocks.

We're computing the drive-time and radius areas around Marshall County, IA — check back shortly. Meanwhile you can drop a pin anywhere in the radius tool.

Census tracts in Marshall County, IA

Name Population Sq mi Per sq mi
Census Tract 9510 4,729 8.0 593
Census Tract 9506 4,592 1.2 3,712
Census Tract 9507 4,309 7.5 576
Census Tract 9505 3,945 2.5 1,603
Census Tract 9508.02 3,586 11.1 323
Census Tract 9508.01 3,471 1.2 2,867
Census Tract 9509 3,393 4.8 700
Census Tract 9503 3,384 165.0 21
Census Tract 9504 3,004 73.6 41
Census Tract 9502 2,942 155.5 19
Census Tract 9501 2,750 142.1 19

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About this page

This page shows demographics for a US county from the 2020 census and the American Community Survey: population, land area, density, urban share, and how the county compares to national averages for income, housing, age, and more.

Counties subdivide into census tracts, listed below with their populations. The drive-time and radius tables measure the population around the county's main population center.

Read how BlockAtlas computes population within an area →