Sierra County, California
County seat: Downieville · Population 3,098 (2025) · 953 sq mi
Sierra County is the 57th most populous of California's 58 counties, with 3,098 people (2025 estimate). Its county seat is Downieville. The map shows its 1 city or town and the 5 neighboring counties.
Sierra County facts
- County seat
- Downieville
- Population (2025 estimate)
- 3,098 −4.2% since 2020
- Land area
- 953 sq mi 45th largest of 58
- Water area
- 9 sq mi
- Population density
- 3 per sq mi
- Established
- 1852
- Named after
- Sierra Nevada mountain range in California and Nevada in the United States
- Largest city
- Loyalton 709
- Median household income
- $63,355
- Cities and towns
- 1 plus 10 CDPs
- ZIP codes
- 11
- Time zone
- Pacific
- FIPS code
- 06091
Cities and towns in Sierra County
Sierra County has 1 incorporated place. Populations count the people living inside Sierra County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Loyalton | City | 709 |
Unincorporated communities (CDPs)
Census-designated places are communities without their own city government; the county provides their services.
| Community | Population | Also in |
|---|---|---|
| Sierra Brooks | 397 | |
| Calpine | 356 | |
| Sierraville | 351 | |
| Sierra City | 250 | |
| Downieville | 126 | |
| Goodyears Bar | 122 | |
| Verdi | 70 | |
| Pike | 34 | |
| Alleghany | 19 | |
| Sattley | 0 |
ZIP codes in Sierra County
11 ZIP codes reach into Sierra County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 89439
- 95910
- 95922 also Yuba County
- 95936
- 95944
- 95960 also Nevada and Yuba counties
- 96105 also Plumas and Lassen counties
- 96118 also Plumas County
- 96124
- 96125
- 96126
Population of Sierra County, 2020–2025
Sierra County shrank by 134 people (−4.2%) between April 2020 and July 2025: 126 more deaths than births and a net loss of 2 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 3,226 |
| 2021 | 3,291 |
| 2022 | 3,203 |
| 2023 | 3,160 |
| 2024 | 3,121 |
| 2025 | 3,098 |
Neighboring counties
- Nevada County southwest · 101,911 people
- Plumas County northwest · 18,583 people
- Yuba County southwest · 88,691 people
- Washoe County, Nevada northeast · 509,386 people
- Lassen County north · 28,117 people
Printable Sierra 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) (121 KB)
- PNG (2400 px) (78 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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