Blog · October 14, 2026 · California
Using the Hillsborough Plat Map
A recorded plat shows how land near San Bruno was divided into lots.
Main page: San Mateo County, CA GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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If a legal description for land in Hillsborough cites a lot number, the Hillsborough plat map is where those numbers come from. In this Hillsborough guide: where to request a copy, plat versus tax map, and the details that matter to buyers.
Who keeps the Hillsborough plat map
For land around San Bruno, the deed or parcel record often names the subdivision and plat reference; that makes the request quick.
Where the parcel data lives
Go first to the San Mateo County parcel viewer; it includes each tax parcel in the county, Burlingame included. With a lot near Belmont, enter a street address, an owner's name or a parcel number, and the matching parcel lights up. In and around Foster City, the parcel card usually lists the owner of record, acreage on the tax roll, a parcel ID and sometimes recent sales.
Land outside a subdivision
Acreage around Burlingame outside a subdivision may have no plat at all; the deed and any recorded survey describe it instead.
Where Hillsborough fits in
The town sits in San Mateo County, California, and the county assessor maps its lots around Daly City. Closer to Foster City, City or town hall handles matters such as zoning, permits and utilities within town limits, while the county keeps the tax map. Lots just outside the town limits out by Belmont usually follows county rules instead.
Land on the county line
San Mateo County borders Alameda County, San Francisco County, Santa Clara County, and Santa Cruz County; every one of them runs a separate parcel map. Acreage along the edge near Millbrae can be split across two assessors' files, so open the neighboring map as well. For a parcel near Burlingame, our state page lists every neighboring county map for California.
Replats and vacations
An amended plat may change lots around Belmont, search the index for replats of the same subdivision; vacated streets or alleys also get recorded.
Two different maps
When the two disagree for a lot near Burlingame, the recorded plat and a survey control.
Details on the Hillsborough plat map
Utility or drainage strips on a lot in Hillsborough stay with the land when it sells; read the notes on the sheet.
How land is described here
California is laid out under the Public Land Survey System, so rural legal descriptions near Millbrae cite section, township and range. A standard section is about one square mile, roughly 640 acres, with 36 sections to a township, though real sections near Burlingame vary in size. Write down the legal description for the tract near San Mateo before you request a deed or survey.
Online indexes and office visits
On ground around Foster City, many recorder offices offer an online index, while others require a visit or a request; copy fees are usually small.
San Mateo County in a few facts
With a lot near Belmont, redwood City is the county seat, which is where the courthouse records live. Other places on the map include Burlingame, San Mateo, Millbrae, and Belmont. Roughly 726,353 people live in San Mateo County (Census Bureau estimate, 2023) spread over some 449 square miles. Features like Don Edwards San Francisco Bay National Wildlife Refuge are easy to spot when you zoom out from Belmont.
Using it on a phone
Most viewers work in a phone browser, handy when you're parked on a road near San Mateo, though signal can drop in rural spots. A screenshot of the parcel near Foster City with its ID is a good backup.
What the map can't tell you
Acreage on the record is an assessed number; only a licensed surveyor establishes the real lines for a parcel near San Bruno. Records update in batches, so a recent sale near Burlingame may not show yet.
Where the recorded documents are
For anything that matters, get the recorded deed from the County Recorder; the parcel map near San Mateo only summarizes it. On ground around San Bruno, have ready the instrument number listed on the parcel record to skip a name search.
Offices that can help
For assessment questions about property around San Mateo belong with the County Assessor, since that office keeps the assessment data. Zoning, permits and septic questions near San Bruno are for the local planning and health departments, and the answer depends on jurisdiction.
Hillsborough: common questions
Is a plat map a survey in Hillsborough?
In and around Belmont, GIS parcels are tax drawings, and the recorded plat is the legal document; trust the plat when they differ.
How do I read lot and block in Hillsborough?
It depends, but it points to a spot on the plat for that subdivision near Foster City, so pull that plat for dimensions.
What is a replat for land near Burlingame?
Short answer: lot splits in Hillsborough go through the planning office, often with a surveyor's drawing.
How do I get a copy of a plat in Hillsborough?
Short answer: recorded plats near Foster City are filed with the County Recorder.
Why do offices ask for the parcel ID near Belmont?
Every office uses it to pull the same file for land near Foster City; you'll see it in the viewer and on tax statements.
Open the official San Mateo 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.