County facts · Land area · October 22, 2026
Largest Counties in Wyoming by Area and Population
The largest Wyoming counties by land area and by 2023 population, plus the smallest, county seats and a link to each official parcel map.
Looking for the largest counties in Wyoming? Wyoming has 23 counties covering about 97,089 square miles of land, based on the Census Bureau's 2020 Gazetteer. The largest by land area is Sweetwater County, at about 10,427 square miles, roughly 5.2 times the size of the smallest, Hot Springs County (2,004 sq mi). Measured by people instead, the largest is Laramie County, with about 100,984 residents in the Census Bureau's July 1, 2023 estimate.
Each table below links the county's Platbookmapper page and its official parcel viewer, so you can go straight from the numbers to the property lines.
Wyoming counties at a glance
- Counties: 23
- Land area: about 97,089 sq mi, plus about 721 sq mi of water inside county lines
- Residents, 2023 estimates: about 584,057, or about 6.0 people per square mile of land
- Median county land area: about 3,997 sq mi
- With a verified public parcel viewer in our directory: 23 of 23
The 10 largest Wyoming counties by land area
| # | County | Seat | Land (sq mi) | 2023 pop. | People per sq mi | Parcel viewer |
|---|---|---|---|---|---|---|
| 1 | Sweetwater County | Green River | 10,427 | 41,249 | 4.0 | TerraGIS |
| 2 | Fremont County | Lander | 9,184 | 39,815 | 4.3 | Beacon (Schneider Geospatial) |
| 3 | Carbon County | Rawlins | 7,898 | 14,334 | 1.8 | TerraGIS |
| 4 | Park County | Cody | 6,939 | 30,735 | 4.4 | TerraGIS |
| 5 | Natrona County | Casper | 5,341 | 79,941 | 15 | ArcGIS Experience Builder |
| 6 | Sublette County | Pinedale | 4,886 | 8,969 | 1.8 | TerraGIS |
| 7 | Campbell County | Gillette | 4,802 | 47,498 | 9.9 | Beacon (Schneider Geospatial) |
| 8 | Albany County | Laramie | 4,274 | 38,257 | 9.0 | TerraGIS |
| 9 | Converse County | Douglas | 4,255 | 13,809 | 3.2 | TerraGIS |
| 10 | Johnson County | Buffalo | 4,154 | 8,759 | 2.1 | TerraGIS |
Together these 10 cover about 64% of Wyoming's land area and hold about 55% of its residents.
The 10 most populous Wyoming counties
| # | County | Seat | 2023 pop. | Land (sq mi) | Parcel viewer |
|---|---|---|---|---|---|
| 1 | Laramie County | Cheyenne | 100,984 | 2,686 | TerraGIS |
| 2 | Natrona County | Casper | 79,941 | 5,341 | ArcGIS Experience Builder |
| 3 | Campbell County | Gillette | 47,498 | 4,802 | Beacon (Schneider Geospatial) |
| 4 | Sweetwater County | Green River | 41,249 | 10,427 | TerraGIS |
| 5 | Fremont County | Lander | 39,815 | 9,184 | Beacon (Schneider Geospatial) |
| 6 | Albany County | Laramie | 38,257 | 4,274 | TerraGIS |
| 7 | Sheridan County | Sheridan | 32,519 | 2,523 | TerraGIS |
| 8 | Park County | Cody | 30,735 | 6,939 | TerraGIS |
| 9 | Teton County | Jackson | 23,232 | 3,997 | TerraGIS |
| 10 | Lincoln County | Kemmerer | 20,880 | 4,075 | county web map |
These 10 hold about 78% of Wyoming's residents in the 2023 estimates.
The 5 smallest Wyoming counties by land area
| County | Seat | Land (sq mi) | 2023 pop. | Parcel viewer |
|---|---|---|---|---|
| Hot Springs County | Thermopolis | 2,004 | 4,661 | TerraGIS |
| Platte County | Wheatland | 2,081 | 8,546 | TerraGIS |
| Uinta County | Evanston | 2,082 | 20,745 | TerraGIS |
| Goshen County | Torrington | 2,226 | 12,642 | Beacon (Schneider Geospatial) |
| Washakie County | Worland | 2,239 | 7,710 | Beacon (Schneider Geospatial) |
Most and least crowded
- Most people per square mile: Laramie County, about 38 (then Natrona County, 15, and Sheridan County, 13)
- Fewest people per square mile: Niobrara County, about 0.9 (then Carbon County, 1.8, and Sublette County, 1.8)
Counties with the most water
The Census Bureau reports water separately from land. It counts lakes, reservoirs, rivers and, along a coast or a Great Lake, the water inside the boundary.
- Teton County: about 220 sq mi of water, 5% of its total area
- Fremont County: about 82 sq mi of water, 1% of its total area
- Carbon County: about 66 sq mi of water, 1% of its total area
Using these numbers in a land search
- Land area is not parcel count. A large rural county can hold fewer parcels than a small suburban one, so size alone says little about how busy its parcel map is.
- Search, don't scroll. In a big county, type an address, owner name or parcel number into the viewer's search box, where it has one, instead of panning across the map.
- Records follow the county line. Deeds, plats and tax bills are kept by the county where the parcel sits, so a tract that crosses a county line usually has a parcel number on each side.
- Rounded figures. Land and water areas are rounded to whole square miles (one decimal for very small places). People per square mile is the 2023 estimate divided by land area.
Related guides
- Wyoming county GIS websites by viewer
- Wyoming landowner maps for hunting
- Montana–Wyoming border counties
- Largest county in each state
- Largest counties in the US by land area
More: All Wyoming counties on Platbookmapper
Sources
- U.S. Census Bureau Gazetteer files, 2020 county land and water area.
- U.S. Census Bureau, Population Estimates Program, county totals, Vintage 2023 (July 1, 2023 estimates)
- Platbookmapper county GIS directory (live data file behind our county pages, pulled October 22, 2026) for each official parcel viewer.
- County seats: Wikidata (county seat property), cross-checked against Census place names.