Dimmit County area

Dimmit County, Texas covers 1,334.5 square miles: 1,328.9 square miles of land and 5.628 square miles of water. Its county seat is Carrizo Springs. An estimated 8,024 people lived there in 2025.

Official Census measurements · GEOID 481272026 Gazetteer · retrieved September 27, 2026
Land area1,328.9 mi²
Water area5.628 mi²
Population (2025)8,024
People per mi²6

County outline

Generalized outline of Dimmit 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 Dimmit County is located

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

Area breakdown

Land accounts for 99.6% of Dimmit County’s measured area and water for 0.4%. Its combined area converts to 3,456.4 square kilometers or approximately 854,088 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land1,328.8853,441.796850,486.4
Water5.62814.5763,601.9
Total1,334.5133,456.373854,088.3

How Dimmit County compares

By original Census land area, Dimmit County ranks #29 of 254 in Texas and #447 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 1.462 times the Texas county-equivalent median of 908.7 square miles. It accounts for 0.5% of the combined county land area in the state.

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

Population and density of Dimmit County

The Census Bureau estimates that 8,024 people lived in Dimmit County on July 1, 2025. That ranks #2,646 of 3,222 county equivalents nationally and #176 of 254 in Texas. Since the April 1, 2020 estimates base of 8,615, the population has declined by 591 (−6.9%), compared with +8.8% for Texas as a whole.

With 1,328.9 square miles of land, that is 6 people per square mile (2.3 per km²), placing Dimmit County #2,804 nationally for density and #189 in Texas. The median county equivalent has 47 people per square mile; the Texas median is 22. Put another way, there are about 106 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate8,5848,4848,3778,2938,2168,024
Change—−100−107−84−77−192

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 Dimmit County

3 incorporated places lie at least partly in Dimmit County. Together they are home to 5,598 people (69.8%); the other 2,426 (30.2%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Carrizo Springs city, with 4,491 residents in the county.

Incorporated placePopulation 2025Since 2020Land mi²
Carrizo Springs cityCounty seat4,491−8.2%3.09
Asherton city659−8.1%0.817
Big Wells city448−7.1%0.555

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

Metropolitan area

Dimmit 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

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

780147882778830788347883678839

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 Dimmit County

Dimmit County shares a land border with 5 county equivalents. It has more land than 3 of them. The largest neighbor is Webb County (3,361.5 mi²) and the smallest is Frio County (1,133.5 mi²). Together with its neighbors, Dimmit County forms a block of 9,887.5 mi² of land, of which it holds 13.4%.

Map of Dimmit County and the 5 county equivalents that border it Webb County, Texas: 3,361.5 mi² landZavala County, Texas: 1,297.4 mi² landMaverick County, Texas: 1,279.5 mi² landLa Salle County, Texas: 1,486.7 mi² landFrio County, Texas: 1,133.5 mi² land
Dimmit 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. DimmitCompare
Webb County3,361.52.5× largerCompare
La Salle County1,486.71.1× largerCompare
Zavala County1,297.4about the sameCompare
Maverick County1,279.5about the sameCompare
Frio County1,133.51.2× smallerCompare

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

Dimmit County has more land than 1 of the 50 states. It is about 1.3 times the land area of Rhode Island (1,033.9 mi²), while Delaware, the next larger state, has 1.5 times as much land (1,948.6 mi²). Texas’s county land could hold about 197 areas the size of Dimmit County.

Land area: Dimmit County and the closest-sized states
Rhode Island1,033.9 mi²
Dimmit County1,328.9 mi²
Delaware1,948.6 mi²

Another way to picture it: the same land area would fill a square about 36.5 miles (58.7 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 Dimmit County?

Dimmit County has more land than 2,775 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Dimmit County1,328.9 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 Dimmit County at #513 nationally by total area, 66 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 0.4%, compared with a national county-equivalent median of 1.2% — 0.7 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 Dimmit County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#446Stark County, North Dakota1,334.9Compare
#447Dimmit County, Texas1,328.9This county
#448Osceola County, Florida1,327.3Compare

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 28.423587, -99.765871. 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: 3,441,795,892 m²; AWATER: 14,576,001 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 Dimmit County?

Dimmit County, Texas has 1,328.9 square miles (3,441.8 km²) of land and 5.628 square miles of water, for a total area of 1,334.5 square miles. It ranks #447 of 3,222 U.S. county equivalents by land area.

Is Dimmit County the largest county in Texas?

No. Dimmit County ranks #29 of 254 in Texas by land area. The largest is Brewster County, with 6,183.8 square miles of land.

What counties border Dimmit County?

Dimmit County shares a land border with Webb County, Zavala County, Maverick County, La Salle County, and Frio County.

What is the population of Dimmit County?

The Census Bureau estimates Dimmit County had 8,024 residents on July 1, 2025, ranking #2,646 of 3,222 county equivalents. That is 6 people per square mile of land.

What is the county seat of Dimmit County?

The county seat of Dimmit County is Carrizo Springs.

What cities and towns are in Dimmit County?

Dimmit County has 3 incorporated places. The most populous are Carrizo Springs city, Asherton city, and Big Wells city; 2,426 residents live outside any incorporated place.

Is Dimmit County part of a metropolitan area?

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

How many ZIP codes are in Dimmit County?

6 ZIP Code Tabulation Areas have land in Dimmit 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 Dimmit County compare with U.S. states?

It has more land than 1 of the 50 states, including Rhode Island (1,033.9 square miles of land).

How many acres of land are in Dimmit County?

The land measurement converts to approximately 850,486 acres. Including water, total area is approximately 854,088 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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