Lassen County, California
County seat: Susanville · Population 28,117 (2025) · 4,541 sq mi
Lassen County is the 48th most populous of California's 58 counties, with 28,117 people (2025 estimate). Its county seat is Susanville. The map shows its 1 city or town and the 5 neighboring counties.
Lassen County facts
- County seat
- Susanville
- Population (2025 estimate)
- 28,117 −14.1% since 2020
- Land area
- 4,541 sq mi 8th largest of 58
- Water area
- 179 sq mi
- Population density
- 6 per sq mi
- Established
- 1864
- Named after
- Peter Lassen American pioneer (1800–1859)
- Largest city
- Susanville 12,816
- Median household income
- $67,403
- Cities and towns
- 1 plus 15 CDPs
- ZIP codes
- 18
- Time zone
- Pacific
- FIPS code
- 06035
Cities and towns in Lassen County
Lassen County has 1 incorporated place. Populations count the people living inside Lassen County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Susanville (county seat) | City | 12,816 |
Unincorporated communities (CDPs)
Census-designated places are communities without their own city government; the county provides their services.
| Community | Population | Also in |
|---|---|---|
| Janesville | 2,399 | |
| Westwood | 1,063 | |
| Johnstonville | 1,039 | |
| Doyle | 779 | |
| Patton Village | 473 | |
| Spaulding | 369 | |
| Bieber | 266 | |
| Herlong | 211 | |
| Clear Creek | 172 | |
| Stones Landing | 85 | |
| Litchfield | 65 | |
| Little Valley | 60 | |
| Nubieber | 7 | |
| Madeline | 0 | |
| Milford | 0 |
ZIP codes in Lassen County
18 ZIP codes reach into Lassen County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 96006 also Modoc County
- 96009
- 96056 also Shasta and Modoc counties
- 96068
- 96105 also Plumas and Sierra counties
- 96109
- 96110 also Modoc County
- 96113
- 96114
- 96117
- 96119
- 96121
- 96123
- 96128
- 96130
- 96132
- 96136
- 96137 also Plumas County
Population of Lassen County, 2020–2025
Lassen County shrank by 4,612 people (−14.1%) between April 2020 and July 2025: 110 more deaths than births and a net loss of 4,618 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 32,349 |
| 2021 | 31,943 |
| 2022 | 30,269 |
| 2023 | 28,694 |
| 2024 | 28,593 |
| 2025 | 28,117 |
Neighboring counties
- Plumas County south · 18,583 people
- Washoe County, Nevada east · 509,386 people
- Modoc County north · 8,426 people
- Shasta County west · 181,648 people
- Sierra County south · 3,098 people
Printable Lassen County map
The PDF is a vector file with real text: it prints sharp on Letter paper and you can search it for a town. The PNG is 2400 pixels wide for slides and documents. Both are free to use with a credit to WhichCounty.
- PDF (Letter) (114 KB)
- PNG (2400 px) (90 KB)
Paste this code to embed the map on your site:
Sources
- Boundaries: U.S. Census Bureau, 2025 Cartographic Boundary Files (1:500,000).
- Population: Census Bureau county and city estimates, Vintage 2025. CDP populations: American Community Survey 2020–2024.
- Places and ZIP codes: Census Bureau 2026 Gazetteer and 2020 ZIP Code Tabulation Area relationship files.
- County seat, founding year and name origin: Wikidata (CC0), checked against state sources.
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