County
Contra Costa County
This is the county layer. It is often the first stop for assessor, tax collector, recorder, court, social service, election, health, sheriff, and unincorporated-area services.
Starting point
Start with the county layer.
County offices are the usual first stop for records, taxes, courts, elections, public health, social services, sheriff services, and unincorporated-area routing.
Cities inside the county can still control city permits, local code, utilities, business licenses, and city-specific rules.
2025 population
1,170,070
Land area
716.901 sq mi
Water area
86.999 sq mi
Directory notes
Local layers to keep on the same page.
Property, taxes, and records
For assessed value, exemptions, ownership records, recording, and tax bills, county offices are usually the starting layer.
Unincorporated land
If an address is outside city limits, county planning, building, environmental health, fire, or public works may handle local permits and code work.
Courts, services, and alerts
Superior court, sheriff, elections, social services, emergency alerts, and health offices often start at the county level.
Practical notes
Office, map, permit, and paperwork notes for Contra Costa County
Place note · Cars and driving · Reviewed July 6, 2026
Antioch BART is the end of the Yellow Line
Antioch Station is a Yellow Line terminal with parking, Tri Delta Transit connections, bike lockers, restrooms, and a train transfer pattern riders should know.
Place note · Outdoors · Reviewed July 6, 2026
Concord picnic sites need the right reservation
Concord park picnics can be casual or reserved, but group sites, alcohol permits, inflatables, deposits, and special-event needs change the plan.
Place note · Cars and driving · Reviewed July 6, 2026
Richmond's BART and Amtrak stop works like a small transit hub
Richmond's Amtrak station sits beside BART and connects with bus and park-and-ride options, but parking rules differ by lot and trip type.
Place note · Outdoors · Reviewed July 6, 2026
Ruth Bancroft Garden makes dry gardening feel alive
Ruth Bancroft Garden in Walnut Creek shows cacti, succulents, and drought-tolerant plants in a walkable garden that feels especially useful in a dry California climate.
Place note · Home and property · Reviewed July 6, 2026
San Ramon trash questions usually run through ACI
San Ramon residential garbage, recycling, organics, missed pickups, cart changes, billing issues, and cleanup days run through ACI of San Ramon.
Place note · Cars and driving · Reviewed July 6, 2026
Walnut Creek downtown parking changes by block, meter, and garage
Walnut Creek downtown parking has different meter zones, garage pricing, and a parking data map that helps show busy blocks by time and place.
Almanac notes
Stories and local context near Contra Costa County
Place note · History and culture
Brentwood's local history museum keeps East County farm memory close
East Contra Costa Historical Museum in Brentwood gives the growing city a place for farm, school, family, and small-town history from the wider East County area.
Place note · History and culture
El Campanil Theatre keeps Antioch's Rivertown stage alive
El Campanil Theatre opened in downtown Antioch in 1928 and now works as a restored cultural venue in the Rivertown district.
Place note · History and culture
Richmond's old Carnegie library now holds city history
The Richmond Museum of History and Culture sits in the old Carnegie Library and connects Ohlone history, early city growth, and the WWII Homefront.
Place note · History and culture
Forest Home Farms keeps San Ramon's farm past in town
Forest Home Farms gives San Ramon a 16-acre historic farm, with Boone family buildings, old outbuildings, a walnut-processing past, and valley agriculture still visible.
Place note · History and culture
Pittsburg's name changed with the work on the waterfront
Pittsburg's history includes Rancho Los Medanos, fishing and canning, Black Diamond coal, waterfront shipping, industry, and Camp Stoneman.
Place note · History and culture
Antioch began as a river landing before it grew south
Antioch's early story starts near the San Joaquin River, where settlers chose the name in 1851 and river travel shaped the town before roads took over.
Place note · History and culture
Clayton's town story starts with Joel Clayton in Diablo Valley
Clayton was laid out in 1857 by Joel Clayton as a small Diablo Valley center for nearby mining, ranching, farming, and local trade.
Place note · History and culture
Moraga's name reaches back to a Californio rancho
Moraga's name connects the town to Joaquin Moraga, Juan Bernal, Rancho Laguna de los Palos Colorados, and Contra Costa's older ranch landscape.