Trinity County area

Trinity County, Texas covers 714 square miles: 693.9 square miles of land and 20.1 square miles of water. Its county seat is Groveton. An estimated 14,384 people lived there in 2025.

Official Census measurements · GEOID 484552026 Gazetteer · retrieved September 27, 2026
Land area693.9 mi²
Water area20.1 mi²
Population (2025)14,384
People per mi²21

County outline

Generalized outline of Trinity 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 Trinity County is located

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

Area breakdown

Land accounts for 97.2% of Trinity County’s measured area and water for 2.8%. Its combined area converts to 1,849.2 square kilometers or approximately 456,943 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land693.8571,797.081444,068.5
Water20.11652.112,874.2
Total713.9731,849.182456,942.7

How Trinity County compares

By original Census land area, Trinity County ranks #218 of 254 in Texas and #1349 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.764 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 Trinity County

The Census Bureau estimates that 14,384 people lived in Trinity County on July 1, 2025. That ranks #2,201 of 3,222 county equivalents nationally and #143 of 254 in Texas. Since the April 1, 2020 estimates base of 13,604, the population has grown by 780 (+5.7%), compared with +8.8% for Texas as a whole.

With 693.9 square miles of land, that is 21 people per square mile (8 per km²), placing Trinity County #2,299 nationally for density and #133 in Texas. The median county equivalent has 47 people per square mile; the Texas median is 22. Put another way, there are about 31 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate13,63613,83713,99214,26514,43414,384
Change—+201+155+273+169−50

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 Trinity County

2 incorporated places lie at least partly in Trinity County. Together they are home to 3,372 people (23.4%); the other 11,012 (76.6%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Trinity city, with 2,450 residents in the county. The county seat, Groveton city, has 922 residents.

Incorporated placePopulation 2025Since 2020Land mi²
Trinity city2,450+4.8%3.791
Groveton cityCounty seat922+0.8%2.583

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

Metropolitan area

Trinity 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

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

7584575847758517585675862758657590475926

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 Trinity County

Trinity County shares a land border with 5 county equivalents. It has more land than 1 of them. The largest neighbor is Houston County (1,231 mi²) and the smallest is San Jacinto County (569.2 mi²). Together with its neighbors, Trinity County forms a block of 5,133.2 mi² of land, of which it holds 13.5%.

Map of Trinity County and the 5 county equivalents that border it Houston County, Texas: 1,231 mi² landPolk County, Texas: 1,057.1 mi² landAngelina County, Texas: 797.9 mi² landWalker County, Texas: 784.2 mi² landSan Jacinto County, Texas: 569.2 mi² land
Trinity 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. TrinityCompare
Houston County1,2311.8× largerCompare
Polk County1,057.11.5× largerCompare
Angelina County797.91.1× largerCompare
Walker County784.21.1× largerCompare
San Jacinto County569.21.2× smallerCompare

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

Trinity County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.5 times as much. Texas’s county land could hold about 377 areas the size of Trinity County.

Land area: Trinity County and the closest-sized states
Trinity County693.9 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 26.3 miles (42.4 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 Trinity County?

Trinity County has more land than 1,873 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Trinity County693.9 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 Trinity County at #1,404 nationally by total area, 55 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 2.8%, compared with a national county-equivalent median of 1.2% — 1.6 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 Trinity County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#1348Monona County, Iowa694.1Compare
#1349Trinity County, Texas693.9This county
#1350San Patricio County, Texas693.3Compare

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 31.096675, -95.151687. 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: 1,797,080,060 m²; AWATER: 52,101,459 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 Trinity County?

Trinity County, Texas has 693.9 square miles (1,797.1 km²) of land and 20.1 square miles of water, for a total area of 714 square miles. It ranks #1349 of 3,222 U.S. county equivalents by land area.

Is Trinity County the largest county in Texas?

No. Trinity County ranks #218 of 254 in Texas by land area. The largest is Brewster County, with 6,183.8 square miles of land.

What counties border Trinity County?

Trinity County shares a land border with Houston County, Polk County, Angelina County, Walker County, and San Jacinto County.

What is the population of Trinity County?

The Census Bureau estimates Trinity County had 14,384 residents on July 1, 2025, ranking #2,201 of 3,222 county equivalents. That is 21 people per square mile of land.

What is the county seat of Trinity County?

The county seat of Trinity County is Groveton.

What cities and towns are in Trinity County?

Trinity County has 2 incorporated places. The most populous are Trinity city and Groveton city; 11,012 residents live outside any incorporated place.

Is Trinity County part of a metropolitan area?

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

How many ZIP codes are in Trinity County?

8 ZIP Code Tabulation Areas have land in Trinity 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 Trinity County compare with U.S. states?

It has less land than every state. Rhode Island, the smallest, has 1.5 times as much land.

How many acres of land are in Trinity County?

The land measurement converts to approximately 444,068 acres. Including water, total area is approximately 456,943 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