County outline
Where Fremont County is located
Area breakdown
Land accounts for 99.1% of Fremont County’s measured area and water for 0.9%. Its combined area converts to 23,998.2 square kilometers or approximately 5,930,074 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 9,183.597 | 23,785.407 | 5,877,502.1 |
| Water | 82.144 | 212.752 | 52,572.2 |
| Total | 9,265.741 | 23,998.159 | 5,930,074.2 |
How Fremont County compares
By original Census land area, Fremont County ranks #2 of 23 in Wyoming and #30 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 2.298 times the Wyoming county-equivalent median of 3,996.8 square miles. It accounts for 9.5% of the combined county land area in the state.
See the complete Wyoming ranking · What counts as a county equivalent?
Population and density of Fremont County
The Census Bureau estimates that 39,464 people lived in Fremont County on July 1, 2025. That ranks #1,224 of 3,222 county equivalents nationally and #5 of 23 in Wyoming. Since the April 1, 2020 estimates base of 39,234, the population has grown by 230 (+0.6%), compared with +2.1% for Wyoming as a whole.
With 9,183.6 square miles of land, that is 4.3 people per square mile (1.7 per km²), placing Fremont County #2,879 nationally for density and #11 in Wyoming. The median county equivalent has 47 people per square mile; the Wyoming median is 4.1. Put another way, there are about 149 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 39,192 | 39,401 | 39,519 | 39,754 | 39,664 | 39,464 |
| Change | — | +209 | +118 | +235 | −90 | −200 |
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 Fremont County
6 incorporated places lie at least partly in Fremont County. Together they are home to 20,446 people (51.8%); the other 19,018 (48.2%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Riverton city, with 10,910 residents in the county. The county seat, Lander city, has 7,379 residents. Among places with at least 1,000 residents in 2020, Riverton city grew fastest since then (+2%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Riverton city | 10,910 | +2% | 10.4 |
| Lander cityCounty seat | 7,379 | −0.3% | 4.686 |
| Dubois town | 984 | +8.3% | 3.48 |
| Shoshoni town | 509 | +6.7% | 4.359 |
| Hudson town | 436 | −0.2% | 0.43 |
| Pavillion town | 228 | +1.8% | 0.201 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Fremont County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Fremont County is a central county of the Riverton, WY Micropolitan Statistical Area. Fremont County is the area’s only county equivalent, so the micro area has the same 9,183.6 square miles of land. By combined land it ranks #8 of 542 micropolitan areas, and #326 by population.
ZIP codes
12 ZIP Code Tabulation Areas have land in Fremont County, and each lies mostly inside the county.
823108250182510825128251382514825158251682520825238264282649
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 Fremont County
Fremont County shares a land border with 8 county equivalents. It has more land than 7 of them. The largest neighbor is Sweetwater County (10,427 mi²) and the smallest is Hot Springs County (2,004.4 mi²). Together with its neighbors, Fremont County forms a block of 52,914.3 mi² of land, of which it holds 17.4%.
| Bordering county equivalent | Land mi² | Size vs. Fremont | Compare |
|---|---|---|---|
| Sweetwater County | 10,427 | 1.1× larger | Compare |
| Carbon County | 7,897.7 | 1.2× smaller | Compare |
| Park County | 6,939 | 1.3× smaller | Compare |
| Natrona County | 5,340.5 | 1.7× smaller | Compare |
| Sublette County | 4,886.5 | 1.9× smaller | Compare |
| Teton County | 3,996.8 | 2.3× smaller | Compare |
| Washakie County | 2,238.7 | 4.1× smaller | Compare |
| Hot Springs County | 2,004.4 | 4.6× smaller | Compare |
How big is Fremont County compared with U.S. states?
Fremont County has more land than 7 of the 50 states. It is about 1 times the land area of New Hampshire (8,954 mi²), while Vermont, the next larger state, has 1 times as much land (9,217.3 mi²). Wyoming’s county land could hold about 11 areas the size of Fremont County.
Another way to picture it: the same land area would fill a square about 95.8 miles (154.2 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 Fremont County?
Fremont County has more land than 3,192 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 Fremont County at #33 nationally by total area, 3 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 0.9%, compared with a national county-equivalent median of 1.2% — 0.3 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 Fremont County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #29 | Pima County, Arizona | 9,188.7 | Compare |
| #30 | Fremont County, Wyoming | 9,183.6 | This county |
| #31 | White Pine County, Nevada | 8,886.7 | 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 43.054831, -108.608935. 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: 23,785,405,175 m²; AWATER: 212,752,229 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 Fremont County?
Fremont County, Wyoming has 9,183.6 square miles (23,785.4 km²) of land and 82.1 square miles of water, for a total area of 9,265.7 square miles. It ranks #30 of 3,222 U.S. county equivalents by land area.
Is Fremont County the largest county in Wyoming?
No. Fremont County ranks #2 of 23 in Wyoming by land area. The largest is Sweetwater County, with 10,427 square miles of land.
What counties border Fremont County?
Fremont County shares a land border with Sublette County, Hot Springs County, Sweetwater County, Natrona County, Park County, Teton County, Carbon County, and Washakie County.
What is the population of Fremont County?
The Census Bureau estimates Fremont County had 39,464 residents on July 1, 2025, ranking #1,224 of 3,222 county equivalents. That is 4.3 people per square mile of land.
What is the county seat of Fremont County?
The county seat of Fremont County is Lander.
What cities and towns are in Fremont County?
Fremont County has 6 incorporated places. The most populous five are Riverton city, Lander city, Dubois town, Shoshoni town, and Hudson town; 19,018 residents live outside any incorporated place.
Is Fremont County part of a metropolitan area?
Yes. It is a central county of the Riverton, WY Micropolitan Statistical Area.
How many ZIP codes are in Fremont County?
12 ZIP Code Tabulation Areas have land in Fremont 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 Fremont County compare with U.S. states?
It has more land than 7 of the 50 states, including New Hampshire (8,954 square miles of land).
How many acres of land are in Fremont County?
The land measurement converts to approximately 5,877,502 acres. Including water, total area is approximately 5,930,074 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.