Blog · October 14, 2026 · California
Antioch GIS Map: looking up parcels
Parcel data for this city comes from the county, and the viewer is free, especially near Clayton.
Main page: Contra Costa County, CA GIS & Parcel Viewer (official map link, county facts and neighboring maps).
Platbookmapper is an Amazon Associate. If you buy through an Amazon link on this page, we earn a commission. The link is a product, not the county map.
For any lot around Clayton, a look at the Antioch GIS map gives you the outline, the owner of record and a parcel ID. In this Antioch guide: which viewer to open, how to search it, and what to double-check with records.
Where the Antioch GIS map lives
Parcel maps here are usually run by the county, not the town, which makes the Contra Costa County parcel viewer the main source for lots in Antioch.
The free map to start with
Go first to the Contra Costa County parcel viewer; it includes each assessed parcel from Oakley to Walnut Creek. If you only know roughly where the land is, zoom in from Pittsburg and select the outline. With a lot near Brentwood, a pop-up or side panel usually lists the owner of record, acreage on the tax roll, the parcel number and often a sale date.
Next door to Contra Costa County
Contra Costa County touches Alameda County, Marin County, Sacramento County, San Francisco County, and San Joaquin County, and each of those keeps its own parcel map. Acreage along the edge near Clayton may show up across two assessors' files, so look at the adjacent map as well. In and around Oakley, our state page lists each neighboring county map for California.
Recorded documents worth pulling
When the details count, request the recorded deed through the County Recorder; the parcel map near Pittsburg only summarizes it. Long-held tracts around Clayton can sit on many deeds, so a title company earns its fee on a real sale.
Getting answers from the right desk
Questions about value or the owner field for land near Oakley go to the County Assessor, since that office keeps the assessment data. Building or septic questions for a lot near Walnut Creek are for the local planning and health departments, and the answer depends on jurisdiction.
Saving what you find
Print or screenshot the parcel near Brentwood with its ID visible, so you have it when calling an office.
Antioch, CA: the basics
Antioch is part of Contra Costa County, California, and the county assessor maps its lots. For a home near Clayton, city or town hall handles matters such as zoning, permits and utilities inside its limits, and the county still keeps the parcel and deed records. Acreage past the city limits toward Oakley usually answers to county rules, not municipal ones.
Limits of the parcel data
The acreage figure is an assessed number; only a licensed surveyor sets the real boundary for a parcel near Oakley. If you're looking near Concord, records update in batches, so a deed recorded last month might lag behind.
How land is described here
California is laid out under the Public Land Survey System, so rural legal descriptions near Concord cite section, township and range. A standard section is about one square mile, roughly 640 acres, and a township holds 36 of them, though corrections make some sections near Pittsburg odd-sized. Write down the legal description for the tract near Concord when you talk to a surveyor.
Getting your bearings
Martinez is the county seat, where most land records are kept. You'll also find Brentwood, Oakley, Pittsburg, and Clayton. About 1,155,025 people call Contra Costa County home (Census Bureau estimate, 2023) across roughly 717 square miles. Features like Clayton-Marsh Creek-Greenville Fault, San Pablo Dam Reservoir, and Mount Diablo State Park help you orient on the aerial around Brentwood.
Browser tips
When the map won't open around Brentwood, switch browsers or turn off pop-up blockers; links occasionally change, and our directory page keeps the current one.
Searching the map
For a house in Antioch, search the street address; for owner searches, try last name first. Near Clayton, searching by parcel number never misses, and it's printed on tax bills.
Taking the map into the field
The parcel map usually runs in a mobile browser, which helps when you're standing on land near Oakley, though signal can drop in rural spots. A saved image of the lot near Pittsburg and its lines helps when you meet an owner or agent.
Beyond the parcel lines
For a tract near Concord, layer lists often include municipal boundaries, floodplain and sometimes zoning; availability varies.
Owner, value and acreage
Recent sales on nearby lots in Antioch are a useful starting point; they're not an appraisal.
Antioch: common questions
How current is the parcel data in Antioch?
For most people, owner data near Oakley can lag new deeds by weeks, so check the deed index.
Are parcel lines on the map exact around Pittsburg?
Good question; lines near Walnut Creek can be off by several feet or more; get a survey before a fence.
Does the map show city limits for Antioch?
On ground around Clayton, many viewers offer aerial imagery plus layers like city limits, zoning or flood zones; open the layer list to see what's there.
Is the Antioch GIS map free?
The Contra Costa County parcel viewer is free and opens without a login, though printing may be limited.
Is the parcel map a survey around Brentwood?
No; boundary questions near Oakley need a licensed surveyor; a survey sets the real corners
Open the official Contra Costa County, CA parcel map See it in the Platbookmapper directory
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey, especially for fences, setbacks, or boundary disputes.