County facts · United States · October 22, 2026
Largest Counties in the US by Land Area
The 25 largest US counties by land area, the biggest in the lower 48, how water changes the order, and a link to each official parcel map.
Looking for the largest counties in the US? By land area the biggest county equivalent is Yukon-Koyukuk Census Area, AK, at about 145,576 square miles, according to the Census Bureau's 2020 Gazetteer. Alaska fills most of the top of the list because its boroughs and census areas are enormous. In the lower 48 the largest is San Bernardino County, CA, at about 20,068 square miles, followed by Coconino County, AZ (18,616 sq mi) and Nye County, NV (18,182 sq mi).
The United States has 3,143 counties and county equivalents in the 2020 Gazetteer. The median one covers about 617 square miles of land, so the giants below are dozens of times the typical size.
The 25 largest US counties by land area
Alaska has no counties. Its entries are boroughs and census areas, the units the Census Bureau counts as county equivalents there.
13 of the 25 are in Alaska. Outside Alaska, the list is all western: Arizona, California, Nevada, Oregon and Wyoming.
The 10 largest counties in the lower 48
| # | County | State | Land (sq mi) | 2023 pop. | Parcel viewer |
|---|---|---|---|---|---|
| 1 | San Bernardino County | California | 20,068 | 2,195,611 | county web map |
| 2 | Coconino County | Arizona | 18,616 | 144,472 | ArcGIS Experience Builder |
| 3 | Nye County | Nevada | 18,182 | 55,720 | County Parcels in Nevada layer in ArcGIS Map Viewer |
| 4 | Elko County | Nevada | 17,173 | 54,293 | county web map |
| 5 | Mohave County | Arizona | 13,332 | 223,682 | county web map |
| 6 | Apache County | Arizona | 11,198 | 65,036 | county web map |
| 7 | Lincoln County | Nevada | 10,633 | 4,452 | County Parcels in Nevada layer in ArcGIS Map Viewer |
| 8 | Sweetwater County | Wyoming | 10,427 | 41,249 | TerraGIS |
| 9 | Inyo County | California | 10,197 | 18,527 | ArcGIS Web AppBuilder |
| 10 | Harney County | Oregon | 10,134 | 7,440 | ORMAP statewide tax lot viewer |
San Bernardino County, CA alone has more land than New Jersey, Massachusetts, Vermont and New Hampshire each, using the same Gazetteer land figures.
Counting water too
The Census Bureau keeps water separate from land. Ranked by land plus water, the top three are Yukon-Koyukuk Census Area, AK (about 147,871 sq mi total), North Slope Borough, AK (about 94,828 sq mi total), Bethel Census Area, AK (about 45,556 sq mi total). Outside Alaska, the largest by total area is San Bernardino County, CA, at about 20,105 square miles including about 37 of water.
What the size of a county means for a parcel search
- Big counties are often thinly settled. Many of the largest have only a few thousand residents, and their parcel maps are dominated by large ranch, forest or public-land tracts.
- Public land shows up as parcels too. In much of the West, federal and state land covers large parts of a county, so expect big agency-owned parcels next to private ones.
- Use the search box. In a county this large, panning to a property is slow. Search the address, owner name or parcel number where the viewer allows it.
Want the biggest county in a single state? See the largest county in each state, or open a state guide such as largest counties in Arizona or largest counties in Alaska.
Related guides
- Most populous counties in the US
- Largest county in each state
- Smallest county in each state
- Smallest counties in the US
- Least populated counties in the US
- Most densely populated counties in the US
- How many counties are in the US
Sources
- U.S. Census Bureau Gazetteer files, 2020 county land and water area (50 states and the District of Columbia; Puerto Rico's municipios are left out).
- 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.