Marshall County area

Population and density of Marshall County

The Census Bureau estimates that 16,255 people lived in Marshall County on July 1, 2025. That ranks #2,083 of 3,222 county equivalents nationally and #43 of 77 in Oklahoma. Since the April 1, 2020 estimates base of 15,299, the population has grown by 956 (+6.2%), compared with +4.1% for Oklahoma as a whole.

With 371.5 square miles of land, that is 44 people per square mile (17 per km²), placing Marshall County #1,671 nationally for density and #28 in Oklahoma. The median county equivalent has 47 people per square mile; the Oklahoma median is 28. Put another way, there are about 15 acres of land per resident.

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 Marshall County

3 incorporated places lie at least partly in Marshall County. Together they are home to 6,588 people (40.5%); the other 9,667 (59.5%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Madill city, with 4,181 residents in the county. Among places with at least 1,000 residents in 2020, Madill city grew fastest since then (+7.5%).

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

Metropolitan area

Marshall 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

3 ZIP Code Tabulation Areas have land in Marshall County, and each lies mostly inside the county.

734397344073446

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Marshall County

Marshall County shares a land border with 5 county equivalents, including 1 in Texas. Each of them has more land than Marshall County. The largest neighbor is Grayson County (932.8 mi²) and the smallest is Love County (513.9 mi²). Together with its neighbors, Marshall County forms a block of 4,187.9 mi² of land, of which it holds 8.9%.

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

Marshall County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.8 times as much. Oklahoma’s county land could hold about 185 areas the size of Marshall County.

Another way to picture it: the same land area would fill a square about 19.3 miles (31 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 Marshall County?

Marshall County has more land than 593 of the other 3,221 county equivalents in the dataset.

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 Marshall County at #2,456 nationally by total area, 173 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.

Its water share is 13%, compared with a national county-equivalent median of 1.2% — 11.8 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 Marshall County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

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.