County Maps US

Lewis County, Missouri

A county in Missouri, ranked 86 of 115 by population.

CountyFIPS 29111

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

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Population
9,879
-163 (-1.6%) since 2020
Land area
505
square miles. A further 1.1% of the total area is water
Population density
19.6
people per square mile, computed rather than published
County seat
Monticello
Seat of county government.
Established
1833
192 years ago
Largest city
Canton city
Population 2,763.

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 Lewis 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 Lewis County, Missouri 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 649 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 Lewis County ranks

Position among the 115 counties of Missouri, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn MissouriNationally
Population9,87986th of 1152,415th of 3,144
Land area505 sq mi79th of 1152,056th of 3,144
Population density19.6 per sq mi82nd of 1152,261st of 3,144
Median household income$59,93458th of 1152,091st of 3,143

Full data for Lewis County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population9,879Vintage 2025 Population Estimates
Population in 202010,042Vintage 2025 Population Estimates
2020 estimates base?10,038Vintage 2025 Population Estimates
Land area505 sq mi2025 Gazetteer Files
Water area5.8 sq mi2025 Gazetteer Files
Total area510.8 sq mi2025 Gazetteer Files
Population density?19.6 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$59,934American Community Survey 2020-2024 5-Year Estimates
Median home value$130,200American Community Survey 2020-2024 5-Year Estimates
Median age37.6American Community Survey 2020-2024 5-Year Estimates
Households3,185American Community Survey 2020-2024 5-Year Estimates
Housing units4,320American 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
+4
136 births, 132 deaths
Net migration
+22
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 Lewis 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
Clark CountyMissouri24 mi6,475
Marion CountyMissouri22 mi28,525
Knox CountyMissouri21 mi3,728
Adams CountyIllinois19 mi64,267
Shelby CountyMissouri6.0 mi5,870
Hancock CountyIllinois3.6 mi16,803

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

All 115 counties of Missouri

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

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