Mills County area

Mills County, Texas covers 749.8 square miles: 748.2 square miles of land and 1.554 square miles of water. Its county seat is Goldthwaite. An estimated 4,580 people lived there in 2025.

Official Census measurements · GEOID 483332026 Gazetteer · retrieved September 27, 2026
Land area748.2 mi²
Water area1.554 mi²
Population (2025)4,580
People per mi²6.1

County outline

Generalized outline of Mills County, Texas
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 Mills County is located

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

Area breakdown

Land accounts for 99.8% of Mills County’s measured area and water for 0.2%. Its combined area converts to 1,941.9 square kilometers or approximately 479,859 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land748.2251,937.894478,864
Water1.5544.025994.6
Total749.7791,941.919479,858.6

How Mills County compares

By original Census land area, Mills County ranks #208 of 254 in Texas and #1179 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.823 times the Texas county-equivalent median of 908.7 square miles. It accounts for 0.3% of the combined county land area in the state.

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

Population and density of Mills County

The Census Bureau estimates that 4,580 people lived in Mills County on July 1, 2025. That ranks #2,924 of 3,222 county equivalents nationally and #203 of 254 in Texas. Since the April 1, 2020 estimates base of 4,454, the population has grown by 126 (+2.8%), compared with +8.8% for Texas as a whole.

With 748.2 square miles of land, that is 6.1 people per square mile (2.4 per km²), placing Mills County #2,801 nationally for density and #187 in Texas. The median county equivalent has 47 people per square mile; the Texas median is 22. Put another way, there are about 105 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate4,4474,4884,4974,5464,5864,580
Change—+41+9+49+40−6

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 Mills County

2 incorporated places lie at least partly in Mills County. Together they are home to 1,904 people (41.6%); the other 2,676 (58.4%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Goldthwaite city, with 1,774 residents in the county.

Incorporated placePopulation 2025Since 2020Land mi²
Goldthwaite cityCounty seat1,774+2.6%2.025
Mullin town130+2.4%0.468

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

Metropolitan area

Mills 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

9 ZIP Code Tabulation Areas have land in Mills County; 4 of them have most of their land inside the county, and the others mainly cover neighboring areas.

764427653176801768447685376864768707688076890

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 Mills County

Mills County shares a land border with 5 county equivalents. It has more land than 1 of them. The largest neighbor is San Saba County (1,135.3 mi²) and the smallest is Lampasas County (712.5 mi²). Together with its neighbors, Mills County forms a block of 5,314.2 mi² of land, of which it holds 14.1%.

Map of Mills County and the 5 county equivalents that border it San Saba County, Texas: 1,135.3 mi² landBrown County, Texas: 944.5 mi² landHamilton County, Texas: 835.9 mi² landLampasas County, Texas: 712.5 mi² landComanche County, Texas: 937.8 mi² land
Mills 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. MillsCompare
San Saba County1,135.31.5× largerCompare
Brown County944.51.3× largerCompare
Comanche County937.81.3× largerCompare
Hamilton County835.91.1× largerCompare
Lampasas County712.51.1× smallerCompare

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

Mills County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.4 times as much. Texas’s county land could hold about 349 areas the size of Mills County.

Land area: Mills County and the closest-sized states
Mills County748.2 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 27.4 miles (44 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 Mills County?

Mills County has more land than 2,043 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Mills County748.2 mi²
Texas median908.7 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 Mills County at #1,282 nationally by total area, 103 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 0.2%, compared with a national county-equivalent median of 1.2% — 1 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 Mills County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#1178Saunders County, Nebraska748.7Compare
#1179Mills County, Texas748.2This county
#1180Blue Earth County, Minnesota747.8Compare

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 31.501883, -98.607232. 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: 1,937,892,764 m²; AWATER: 4,023,558 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 Mills County?

Mills County, Texas has 748.2 square miles (1,937.9 km²) of land and 1.554 square miles of water, for a total area of 749.8 square miles. It ranks #1179 of 3,222 U.S. county equivalents by land area.

Is Mills County the largest county in Texas?

No. Mills County ranks #208 of 254 in Texas by land area. The largest is Brewster County, with 6,183.8 square miles of land.

What counties border Mills County?

Mills County shares a land border with San Saba County, Brown County, Hamilton County, Lampasas County, and Comanche County.

What is the population of Mills County?

The Census Bureau estimates Mills County had 4,580 residents on July 1, 2025, ranking #2,924 of 3,222 county equivalents. That is 6.1 people per square mile of land.

What is the county seat of Mills County?

The county seat of Mills County is Goldthwaite.

What cities and towns are in Mills County?

Mills County has 2 incorporated places. The most populous are Goldthwaite city and Mullin town; 2,676 residents live outside any incorporated place.

Is Mills County part of a metropolitan area?

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

How many ZIP codes are in Mills County?

9 ZIP Code Tabulation Areas have land in Mills County, and 4 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

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

It has less land than every state. Rhode Island, the smallest, has 1.4 times as much land.

How many acres of land are in Mills County?

The land measurement converts to approximately 478,864 acres. Including water, total area is approximately 479,859 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

Download the complete CSV or JSON dataset