Largest US Counties by Area

The largest county in America isn't in Texas or California — it's Yukon-Koyukuk Census Area, Alaska, at 145,769 square miles of land. That's bigger than all but a handful of US states — it's even slightly larger than the entire state of Montana (145,550 sq mi). Second place goes to Alaska's North Slope Borough (88,793 sq mi), and third to Bethel Census Area (40,661 sq mi).

In fact, 14 of the 30 largest counties are in Alaska, whose boroughs and census areas were drawn at a continental scale. The biggest county in the Lower 48 is San Bernardino County, California (20,068 sq mi) — itself larger than nine US states — followed by Coconino County, Arizona and Nye County, Nevada. The 30th-largest, Fremont County, Wyoming, still covers 9,184 square miles.

How to read this table

Counties are ranked by land area (inland water excluded), so lake-heavy counties don't get an unfair boost. "County" includes county equivalents: Alaska's boroughs and census areas function as counties for statistical purposes.

To explore further, view any county's exact borders with the county boundary viewer, measure your own areas with the map area calculator, or convert between units with the acreage map calculator.