Maries County area

Maries County, Missouri covers 529.9 square miles: 526.9 square miles of land and 2.947 square miles of water. Its county seat is Vienna. An estimated 8,397 people lived there in 2025.

Official Census measurements · GEOID 291252026 Gazetteer · retrieved September 27, 2026
Land area526.9 mi²
Water area2.947 mi²
Population (2025)8,397
People per mi²16

County outline

Generalized outline of Maries County, Missouri
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 Maries County is located

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

Area breakdown

Land accounts for 99.4% of Maries County’s measured area and water for 0.6%. Its combined area converts to 1,372.3 square kilometers or approximately 339,109 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land526.9111,364.693337,223
Water2.9477.6331,886.1
Total529.8581,372.326339,109.1

How Maries County compares

By original Census land area, Maries County ranks #74 of 115 in Missouri and #1987 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.89 times the Missouri county-equivalent median of 592 square miles. It accounts for 0.8% of the combined county land area in the state.

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

Population and density of Maries County

The Census Bureau estimates that 8,397 people lived in Maries County on July 1, 2025. That ranks #2,625 of 3,222 county equivalents nationally and #97 of 115 in Missouri. Since the April 1, 2020 estimates base of 8,431, the population has declined by 34 (−0.4%), compared with +1.9% for Missouri as a whole.

With 526.9 square miles of land, that is 16 people per square mile (6.2 per km²), placing Maries County #2,443 nationally for density and #89 in Missouri. The median county equivalent has 47 people per square mile; the Missouri median is 31. Put another way, there are about 40 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate8,4558,4268,4418,4528,4948,397
Change—−29+15+11+42−97

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 Maries County

3 incorporated places lie at least partly in Maries County. Together they are home to 1,740 people (20.7%); the other 6,657 (79.3%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Belle city, with 1,166 residents in the county (the city extends into 1 other county). The county seat, Vienna city, has 572 residents.

Incorporated placePopulation 2025Since 2020Land mi²
Belle cityAlso in 1 other county1,166−0.5%1.335
Vienna cityCounty seat572−0.5%1.068
Argyle townAlso in 1 other county20%0.403

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Maries County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Maries 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

10 ZIP Code Tabulation Areas have land in Maries County; 7 of them have most of their land inside the county, and the others mainly cover neighboring areas.

65001650136501465058654016544365459655596558065582

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 Maries County

Maries County shares a land border with 5 county equivalents. It has more land than 1 of them. The largest neighbor is Phelps County (671.8 mi²) and the smallest is Gasconade County (519 mi²). Together with its neighbors, Maries County forms a block of 3,464.1 mi² of land, of which it holds 15.2%.

Map of Maries County and the 5 county equivalents that border it Osage County, Missouri: 606.5 mi² landPhelps County, Missouri: 671.8 mi² landMiller County, Missouri: 592.7 mi² landGasconade County, Missouri: 519 mi² landPulaski County, Missouri: 547.2 mi² land
Maries 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. MariesCompare
Phelps County671.81.3× largerCompare
Osage County606.51.2× largerCompare
Miller County592.71.1× largerCompare
Pulaski County547.2about the sameCompare
Gasconade County519about the sameCompare

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

Maries 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 times as much. Missouri’s county land could hold about 130 areas the size of Maries County.

Land area: Maries County and the closest-sized states
Maries County526.9 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 23 miles (36.9 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 Maries County?

Maries County has more land than 1,235 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Maries County526.9 mi²
Missouri median592 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 Maries County at #2,072 nationally by total area, 85 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 0.6%, compared with a national county-equivalent median of 1.2% — 0.6 percentage points lower. 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 Maries County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#1986Hampshire County, Massachusetts527.2Compare
#1987Maries County, Missouri526.9This county
#1988Fulton County, Georgia526.9Compare

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 38.162615, -91.923601. 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: 1,364,692,499 m²; AWATER: 7,632,378 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 Maries County?

Maries County, Missouri has 526.9 square miles (1,364.7 km²) of land and 2.947 square miles of water, for a total area of 529.9 square miles. It ranks #1987 of 3,222 U.S. county equivalents by land area.

Is Maries County the largest county in Missouri?

No. Maries County ranks #74 of 115 in Missouri by land area. The largest is Texas County, with 1,177.3 square miles of land.

What counties border Maries County?

Maries County shares a land border with Osage County, Phelps County, Miller County, Gasconade County, and Pulaski County.

What is the population of Maries County?

The Census Bureau estimates Maries County had 8,397 residents on July 1, 2025, ranking #2,625 of 3,222 county equivalents. That is 16 people per square mile of land.

What is the county seat of Maries County?

The county seat of Maries County is Vienna.

What cities and towns are in Maries County?

Maries County has 3 incorporated places. The most populous are Belle city, Vienna city, and Argyle town; 6,657 residents live outside any incorporated place.

Is Maries County part of a metropolitan area?

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

How many ZIP codes are in Maries County?

10 ZIP Code Tabulation Areas have land in Maries County, and 7 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

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

It has less land than every state. Rhode Island, the smallest, has 2 times as much land.

How many acres of land are in Maries County?

The land measurement converts to approximately 337,223 acres. Including water, total area is approximately 339,109 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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