County Maps US

Lassen County, California

A county in California, ranked 48 of 58 by population.

CountyFIPS 06035

Within California
Lassen County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data. The dot marks Susanville, the county seat, located via the 2025 Census Gazetteer.

Download SVGFull California map downloads

Population
28,117
-4,232 (-13.1%) since 2020
Land area
4,541
square miles. A further 3.8% of the total area is water
Population density
6.2
people per square mile, computed rather than published
County seat
Susanville
Seat of county government.
Established
1864
161 years ago
Largest city
Susanville city
Population 12,816.

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Satellite view

Aerial imagery of Lassen County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Lassen County, California from the USGS National Map, with its boundary outlined
Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 578 by 800 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Lassen County ranks

Position among the 58 counties of California, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn CaliforniaNationally
Population28,11748th of 581,507th of 3,144
Land area4,541 sq mi8th of 5898th of 3,144
Population density6.2 per sq mi52nd of 582,719th of 3,144
Median household income$67,40346th of 581,395th of 3,143

Full data for Lassen County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population28,117Vintage 2025 Population Estimates
Population in 202032,349Vintage 2025 Population Estimates
2020 estimates base?32,729Vintage 2025 Population Estimates
Land area4,541 sq mi2025 Gazetteer Files
Water area178.7 sq mi2025 Gazetteer Files
Total area4,720 sq mi2025 Gazetteer Files
Population density?6.2 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$67,403American Community Survey 2020-2024 5-Year Estimates
Median home value$265,300American Community Survey 2020-2024 5-Year Estimates
Median age38.3American Community Survey 2020-2024 5-Year Estimates
Households9,247American Community Survey 2020-2024 5-Year Estimates
Housing units12,231American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths
-21
230 births, 251 deaths
Net migration
-451
More people moved out than moved in.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 5 areas bordering Lassen County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering areaStateShared borderPopulation
Plumas CountyCalifornia136 mi18,583
Washoe CountyNevada101 mi509,386
Modoc CountyCalifornia69 mi8,426
Shasta CountyCalifornia52 mi181,648
Sierra CountyCalifornia8.7 mi3,098

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

All 58 counties of California

Open the interactive California county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.