County outline
Where Trinity County is located
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
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 693.857 | 1,797.081 | 444,068.5 |
| Water | 20.116 | 52.1 | 12,874.2 |
| Total | 713.973 | 1,849.182 | 456,942.7 |
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.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 13,636 | 13,837 | 13,992 | 14,265 | 14,434 | 14,384 |
| 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 place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Trinity city | 2,450 | +4.8% | 3.791 |
| Groveton cityCounty seat | 922 | +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%.
| Bordering county equivalent | Land mi² | Size vs. Trinity | Compare |
|---|---|---|---|
| Houston County | 1,231 | 1.8× larger | Compare |
| Polk County | 1,057.1 | 1.5× larger | Compare |
| Angelina County | 797.9 | 1.1× larger | Compare |
| Walker County | 784.2 | 1.1× larger | Compare |
| San Jacinto County | 569.2 | 1.2× smaller | Compare |
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.
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.
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 rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1348 | Monona County, Iowa | 694.1 | Compare |
| #1349 | Trinity County, Texas | 693.9 | This county |
| #1350 | San Patricio County, Texas | 693.3 | Compare |
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.
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.