Duchesne County area

Duchesne County, Utah covers 3,250.5 square miles: 3,235.5 square miles of land and 15 square miles of water. Its county seat is Duchesne. An estimated 20,856 people lived there in 2025.

Official Census measurements · GEOID 490132026 Gazetteer · retrieved September 27, 2026
Land area3,235.5 mi²
Water area15 mi²
Population (2025)20,856
People per mi²6.4

County outline

Generalized outline of Duchesne County, Utah
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 Duchesne County is located

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

Area breakdown

Land accounts for 99.5% of Duchesne County’s measured area and water for 0.5%. Its combined area converts to 8,418.8 square kilometers or approximately 2,080,325 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land3,235.5238,379.9662,070,734.7
Water14.98538.8119,590.4
Total3,250.5088,418.7772,080,325.1

How Duchesne County compares

By original Census land area, Duchesne County ranks #12 of 29 in Utah and #158 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 1.333 times the Utah county-equivalent median of 2,427.6 square miles. It accounts for 3.9% of the combined county land area in the state.

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

Population and density of Duchesne County

The Census Bureau estimates that 20,856 people lived in Duchesne County on July 1, 2025. That ranks #1,841 of 3,222 county equivalents nationally and #15 of 29 in Utah. Since the April 1, 2020 estimates base of 19,604, the population has grown by 1,252 (+6.4%), compared with +8.2% for Utah as a whole.

With 3,235.5 square miles of land, that is 6.4 people per square mile (2.5 per km²), placing Duchesne County #2,786 nationally for density and #17 in Utah. The median county equivalent has 47 people per square mile; the Utah median is 11. Put another way, there are about 99 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate19,61719,79820,15620,48420,67620,856
Change—+181+358+328+192+180

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 Duchesne County

5 incorporated places lie at least partly in Duchesne County. Together they are home to 9,770 people (46.8%); the other 11,086 (53.2%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Roosevelt city, with 7,032 residents in the county. The county seat, Duchesne city, has 1,722 residents. Among places with at least 1,000 residents in 2020, Duchesne city grew fastest since then (+8%).

Incorporated placePopulation 2025Since 2020Land mi²
Roosevelt city7,032+3.9%7.215
Duchesne cityCounty seat1,722+8%2.786
Myton city586+5.6%1.013
Altamont town270+8%0.272
Tabiona town160+6.7%0.12

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

Metropolitan area

Duchesne 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

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

840018400284007840218402784031840518405284053840668407284073

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 Duchesne County

Duchesne County shares a land border with 6 county equivalents. It has more land than 5 of them. The largest neighbor is Uintah County (4,482.9 mi²) and the smallest is Daggett County (696.5 mi²). Together with its neighbors, Duchesne County forms a block of 14,946.4 mi² of land, of which it holds 21.6%.

Map of Duchesne County and the 6 county equivalents that border it Uintah County, Utah: 4,482.9 mi² landWasatch County, Utah: 1,177 mi² landSummit County, Utah: 1,870.7 mi² landCarbon County, Utah: 1,479.3 mi² landUtah County, Utah: 2,004.5 mi² landDaggett County, Utah: 696.5 mi² land
Duchesne 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. DuchesneCompare
Uintah County4,482.91.4× largerCompare
Utah County2,004.51.6× smallerCompare
Summit County1,870.71.7× smallerCompare
Carbon County1,479.32.2× smallerCompare
Wasatch County1,1772.7× smallerCompare
Daggett County696.54.6× smallerCompare

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

Duchesne County has more land than 2 of the 50 states. It is about 1.7 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 1.5 times as much land (4,842.5 mi²). Utah’s county land could hold about 26 areas the size of Duchesne County.

Land area: Duchesne County and the closest-sized states
Delaware1,948.6 mi²
Duchesne County3,235.5 mi²
Connecticut4,842.5 mi²

Another way to picture it: the same land area would fill a square about 56.9 miles (91.5 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 Duchesne County?

Duchesne County has more land than 3,064 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Duchesne County3,235.5 mi²
Utah median2,427.6 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 Duchesne County at #170 nationally by total area, 12 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 0.5%, 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 Duchesne County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#157Gunnison County, Colorado3,239.1Compare
#158Duchesne County, Utah3,235.5This county
#159Rio Blanco County, Colorado3,221Compare

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 40.289393, -110.429584. 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: 8,379,965,580 m²; AWATER: 38,811,228 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 Duchesne County?

Duchesne County, Utah has 3,235.5 square miles (8,380 km²) of land and 15 square miles of water, for a total area of 3,250.5 square miles. It ranks #158 of 3,222 U.S. county equivalents by land area.

Is Duchesne County the largest county in Utah?

No. Duchesne County ranks #12 of 29 in Utah by land area. The largest is San Juan County, with 7,823.7 square miles of land.

What counties border Duchesne County?

Duchesne County shares a land border with Uintah County, Wasatch County, Summit County, Carbon County, Utah County, and Daggett County.

What is the population of Duchesne County?

The Census Bureau estimates Duchesne County had 20,856 residents on July 1, 2025, ranking #1,841 of 3,222 county equivalents. That is 6.4 people per square mile of land.

What is the county seat of Duchesne County?

The county seat of Duchesne County is Duchesne.

What cities and towns are in Duchesne County?

Duchesne County has 5 incorporated places. The most populous are Roosevelt city, Duchesne city, Myton city, Altamont town, and Tabiona town; 11,086 residents live outside any incorporated place.

Is Duchesne County part of a metropolitan area?

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

How many ZIP codes are in Duchesne County?

12 ZIP Code Tabulation Areas have land in Duchesne County, and 12 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

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

It has more land than 2 of the 50 states, including Delaware (1,948.6 square miles of land).

How many acres of land are in Duchesne County?

The land measurement converts to approximately 2,070,735 acres. Including water, total area is approximately 2,080,325 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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