When was Sierra County founded?

Sierra County was founded in 1852, formed from Yuba County, and named after Sierra Nevada.

What is the county seat of Sierra County?

The county seat of Sierra County is Downieville.

Is there an online parcel map for Sierra County?

Yes. Sierra County publishes a parcel map of 4,840 parcels, rated fallback here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Sierra County's boundary or name changed?

Sierra County was created in 1852 from Yuba County. Since then the Atlas of Historical County Boundaries records 7 later changes, chiefly involving Plumas County, Nevada County and Lassen County.

Who issues building permits in Sierra County?

The county's page on building permits: Permit. Inside a city or town, ask that city first.

Who issues septic and well permits in Sierra County?

The county's page on septic systems and wells: Behavioral Health.

Is my lot in a flood zone?

We do not have flood maps for Sierra County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Sierra County, California: parcels, history and offices

Where it is

Sierra on the map of California

California has 58 counties and county equivalents, each with its own records office. Shapes with a page are links.

Counties of California · Sierra highlighted

History

Formed in 1852 from Yuba County

An old deed may name a county that no longer exists, or a boundary that has since moved.

Sierra County was formed in 1852 from Yuba County, and named after Sierra Nevada. Downieville is the county seat.

Deeds and plats from before 1852 for land now in Sierra County may have been recorded in Yuba County.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries; the 5 that matter most are shown first.

1852
Sierra County created Sierra created from Yuba.
from Yuba
16 April 1852 · Calif. Stats. 1852, 3d sess., ch. 145/pp. 230-231
1852
Lost territory Sierra lost to Nevada.
to Nevada
3 May 1852 · Calif. Stats. 1852, 3d sess., chs. 114-115/pp. 190-192
1856
Lost territory Sierra lost to Nevada.
to Nevada
19 April 1856 · Calif. Stats. 1856, 7th sess., ch. 122/p. 143
1863
Gained territory Sierra gained from Plumas.
from Plumas
27 March 1863 · Calif. Stats. 1863, 14th sess., ch. 101/p. 114; Sinnott, 6:19-22
1866
Gained territory Sierra gained from Yuba.
from Yuba
13 March 1866 · Calif. Stats. 1865, 16th sess., ch. 229/p. 228

Show all 10 changes (5 more, mostly small adjustments)

1852
Sierra County created Sierra created from Yuba.
from Yuba
16 April 1852 · Calif. Stats. 1852, 3d sess., ch. 145/pp. 230-231
1852
Lost territory Sierra lost to Nevada.
to Nevada
3 May 1852 · Calif. Stats. 1852, 3d sess., chs. 114-115/pp. 190-192
1856
Lost territory Sierra lost to Nevada.
to Nevada
19 April 1856 · Calif. Stats. 1856, 7th sess., ch. 122/p. 143
1863
Gained territory Sierra gained from Plumas.
from Plumas
27 March 1863 · Calif. Stats. 1863, 14th sess., ch. 101/p. 114; Sinnott, 6:19-22
1866
Gained territory Sierra gained from Yuba.
from Yuba
13 March 1866 · Calif. Stats. 1865, 16th sess., ch. 229/p. 228
1866
Lost territory Sierra lost to Plumas.
to Plumas
31 March 1866 · Calif. Stats. 1865, 16th sess., ch. 466/p. 605
1868
Gained territory Sierra gained small area from Plumas.
from Plumas
28 March 1868 · Calif. Stats. 1867, 17th sess., ch. 377/p. 462
1874
Gained territory Sierra gained from Lassen and Plumas when boundary was set on public land survey lines.
from Lassen from Plumas
16 March 1874 · Calif. Stats. 1873, 20th sess., Acts Amendatory of the Codes, p. 166
1908
Changed California Supreme Court settled boundary dispute between Sierra and Nevada in favor of Sierra. Dispute grew out of disagreement over the location of the source of the South Fork of Middle Yuba River (no change).
Nevada
28 December 1908 · "Sierra County v. Nevada County," in Calif. Rpts., 155:1-15
1909
Boundary clarified Sierra boundaries clarified (no change).
no change
1 March 1909 · Calif. Stats. 1909, 38th sess., ch. 75, sec. 1/p. 86

Land and parcels

What the maps cover in Sierra

Who publishes each layer, how good it is, and when we last checked.

Parcels Fallback

Lot lines and tax-map numbers for 4,840 parcels from Sierra County. Drawn for tax purposes: usually within a few feet of a survey, but not a survey. This copy is a fallback, not the county's own: use it as a guide and check the official record.
edited 21 September 2023 · checked 15 October 2026
Address points Missing

No public address points layer found for Sierra County yet.
Buildings Reference

Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026

Official: from the office that keeps the record
Good enough: a reliable statewide or national copy
Fallback: a guide only; check the official record
Missing: nothing public found yet

People and land

Sierra by the Census

Population

3,236 2020 Census count

Housing units

2,127 2020 Census count

Land area

953 square miles

Water area

9 square miles

People per sq mi

3 population ÷ land area

Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.

Rules and offices

Who to ask before you build, dig or sell

Official county pages only. We link to them; we do not copy them, because they change.

Inside a city or town, permits usually come from that city rather than the county.

Records

Assessor and property recordsfrom sierracounty.ca.gov · checked 14 October 2026
Clerk of court: deeds and plats
Clerk-Recorder
from sierracounty.ca.gov · checked 14 October 2026

Permits

Health department: septic and wellfrom sierracounty.ca.gov · checked 14 October 2026
Permitfrom sierracounty.ca.gov
Other Permitsfrom sierracounty.ca.gov
Septicfrom sierracounty.ca.gov
Water Well Testingfrom sierracounty.ca.gov

Zoning and code

Planning and zoningfrom sierracounty.ca.gov · checked 14 October 2026
Ordinance Codefrom sierracounty.ca.gov
Ordinance 1041from sierracounty.ca.gov
Zoningfrom sierracounty.ca.gov

County government

County government
The official website of Sierra County.
sierracounty.ca.gov

See your own lot on these maps

Open Sierra County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.

Open the free map no sign-in Pro early access

Questions

Common questions about Sierra County

When was Sierra County founded?: Sierra County was founded in 1852, formed from Yuba County, and named after Sierra Nevada.
What is the county seat of Sierra County?: The county seat of Sierra County is Downieville.
Is there an online parcel map for Sierra County?: Yes. Sierra County publishes a parcel map of 4,840 parcels, rated fallback here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Sierra County's boundary or name changed?: Sierra County was created in 1852 from Yuba County. Since then the Atlas of Historical County Boundaries records 7 later changes, chiefly involving Plumas County, Nevada County and Lassen County.
Who issues building permits in Sierra County?: The county's page on building permits: Permit. Inside a city or town, ask that city first.
Who issues septic and well permits in Sierra County?: The county's page on septic systems and wells: Behavioral Health.
Is my lot in a flood zone?: We do not have flood maps for Sierra County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby

Sierra CountyCalifornia