Contra Costa County · county:06013
Geometry registry artifact: ca-counties.geojson
California · county
Contra Costa County
FIPS 06013county:06013DerivedAlso indexed as: Contra Costa
A permanent, source-linked view of the county's 2016, 2020, and 2024 presidential history, turnout, election-administration context, and non-conclusive review signals.
Presidential results
2016–2024 county history
| Year | Democratic | Republican | Other | Total | Winner / margin | Confidence | Source |
|---|---|---|---|---|---|---|---|
| 2016 | 319,287Hillary Clinton · 68.49% | 115,956Donald Trump · 24.87% | 30,932 | 466,175 | Democratic +203,331 (43.62%) | Exact | Historical county presidential baseline rows |
| 2020 | 416,386Joe Biden · 71.63% | 152,877Donald Trump · 26.30% | 12,053 | 581,316 | Democratic +263,509 (45.33%) | Exact | Historical county presidential baseline rows |
| 2024 | 356,008Kamala Harris · 67.30% | 155,308Donald Trump · 29.36% | 17,671 | 528,987 | Democratic +200,700 (37.94%) | Derived | Official presidential county results |
“Other” includes all other loaded presidential candidates and write-ins. Margin is the absolute gap between the Democratic and Republican vote buckets, divided by all loaded presidential votes.
Participation
2024 turnout context
- Ballots cast
- 539,219
- Registered voters
- 722,861
- Reported/calculated rate
- 74.60%
- Reporting grain
- county
California SOS registered-voter totals from the 15-day Report of Registration; Same Day Voter Registration after the 15-day close is not included in registered-voter totals.
Official voter participation and registration county turnout rowsAdministration context
Vote methods
No county-tagged vote-method rows are available.
Administration context
Voting equipment
Equipment metadata is jurisdiction context only. It is not a vote or turnout row, does not prove or disprove an advisory signal, and does not guarantee every precinct or ballot mode used one identical setup.
| Vendor | System | Type / use | Paper record | Tabulation | Confidence | Source |
|---|---|---|---|---|---|---|
| Dominion | Dominion ImageCast X BMD + | Optical Scan · county_context | hand_marked_paper | Optical Scan | Proxy | Source |
Review context
Advisory indicators
These calculated indicators are prompts for checking source data, reporting grain, denominators, and local context. They are not evidence or findings of fraud, misconduct, or an incorrect election outcome.
No county-tagged advisory indicators are currently published for this profile.
Traceability
Sources and provenance
Historical county presidential baseline rows
California Secretary of State
Official California Secretary of State county presidential baselines used for historical context only. Individual rows carry the per-year Statement of Vote workbook URL.Open sourceOfficial presidential county results
California Secretary of State
Official California Secretary of State Statement of Vote workbook normalized to county rows by scripts/normalize-ca-sov-workbooks.mjs.Open sourceOfficial voter participation and registration county turnout rows
California Secretary of State
Official California Secretary of State county participation table normalized by scripts/normalize-ca-turnout.mjs from the saved PDF artifact data/ca-2024-voter-participation-stats-by-county.pdf.Open sourceVerified Voting Verifier CA 2024 equipment context
Verified Voting
Verified Voting Verifier data is jurisdiction-level election-administration context. Most rows are counties, but some states report state-level rows and some county rows can summarize mixed tabulation, accessible-device, absentee, poll-book, or other configurations. Treat it as source-linked context, not proof every precinct in a county used one identical setup, and not a turnout or vote-result source.Open source