Blog · October 14, 2026 · California
Using the Belmont Plat Map
Lots in Belmont trace back to recorded plats filed with the county.
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 Belmont cites a lot number, look up the Belmont plat map it refers to. What this Belmont guide covers: where plats are filed, how a plat differs from a parcel map, and the details that matter to buyers.
Getting started with the Belmont plat map
For land around Burlingame, look for the plat book reference on the parcel record; use it to request a copy.
Opening the official parcel viewer
Your first stop is the San Mateo County parcel viewer; it covers each tax parcel from Redwood City to Hillsborough. When a rural tract has no street number, pan along the nearest road and click the parcel itself, whether the land is near Burlingame or elsewhere in the county. In and around Foster City, write down the parcel ID from that panel; each records desk in the county uses it to find the file.
Offices that can help
For assessment questions about property around Burlingame are handled by the County Assessor, which maintains the tax roll. Zoning, permits and septic questions near San Mateo need the planning or permitting office, depending on whether the land is inside town limits.
Amended plats
Lots near Redwood City can be combined or reconfigured by a replat, search the index for replats of the same subdivision; street vacations near San Mateo show up in the records too.
Metes and bounds instead
Acreage around San Mateo outside a subdivision may have no plat at all; the deed and any recorded survey describe it instead.
Taking the map into the field
The parcel map usually runs in a mobile browser, useful out on a road near Foster City, though signal can drop in rural spots. A saved image of the lot near Foster City and its lines keeps working without signal.
Deeds, plats and who keeps them
The map is an index, not the title: deeds, plats and easements for land near Burlingame sit with the County Recorder. Long-held tracts around San Carlos can sit on several deeds, so a title company is worth hiring on a real sale.
Where Belmont fits in
Belmont lies within San Mateo County, California, and the county assessor maps its lots. For a home near Foster City, the municipality handles things like zoning, permits and utilities for lots inside the boundary, while the county keeps the tax map. Acreage past the city limits out by San Carlos often falls under county rules rather than the town's.
Two different maps
When the two disagree for a lot near Foster City, go with the plat and a surveyor's work.
Land on the county line
San Mateo County meets Alameda County, San Francisco County, Santa Clara County, and Santa Cruz County, all with their own assessor records. A tract near the line by San Carlos may be split in two county records, so look at the adjacent map as well. On ground around Foster City, the Platbookmapper state page links every neighboring county map for California.
Reading the plat sheet
Recorded easements around San Carlos stay with the land when it sells; read the notes on the sheet.
Sections, lots and bearings
California is laid out under the Public Land Survey System, so deeds around San Mateo reference sections and townships. Each section is nominally a mile square, about 640 acres, with 36 sections to a township, though real sections near San Carlos vary in size. Copy the legal description from the record for the parcel near Burlingame before you request a deed or survey.
Places you'll see on the map
Redwood City serves as the county seat, which is where the courthouse records live. Other places on the map include San Carlos, San Mateo, and Foster City, each with its own cluster of lots. Around 726,353 people live in San Mateo County (Census estimate, 2023) across roughly 449 square miles. Places such as Don Edwards San Francisco Bay National Wildlife Refuge make handy reference points on the map near Burlingame.
A word on accuracy
Tax maps are drawn for assessment, not surveyed, so the edge of a yard near Burlingame often sits several feet off the line on screen. On ground around San Mateo, records update in batches, so a deed recorded last month can take weeks to appear.
Requesting the plat
If you're looking near San Mateo, some counties put plat images online, while others require a visit or a request; copy fees are usually small.
Quick answers
Where are historic plats for Belmont?
For most people, older plats near Foster City may be on film or paper, including older subdivisions.
What is a replat around Hillsborough?
Usually, lot splits in Belmont go through the planning office, often with a surveyor's drawing.
How is a plat different from the parcel map near San Mateo?
It depends, but the plat near Foster City is recorded, while the GIS layer is an approximation.
How do I get a copy of a plat in Belmont?
For most people, recorded plats near Foster City are filed with the County Recorder.
Does the parcel map work on a phone near Foster City?
The map near San Mateo usually works on a phone; screenshots help offline.
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.