Blog · October 14, 2026 · California
Half Moon Bay Plat Map: finding the recorded plat
A recorded plat shows how land near San Mateo 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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Checking easements on a house in Half Moon Bay? Start with the Half Moon Bay plat map, because the recorded plat shows how the land was divided. This Half Moon Bay guide covers: where plats are filed, how a plat differs from a parcel map, and the details that matter to buyers.
Tracking down the Half Moon Bay plat map
For a subdivision near Belmont, the deed or parcel record often names the subdivision and plat reference; that makes the request quick.
Where the parcel data lives
Begin with the San Mateo County parcel viewer; it includes every tax parcel around Hillsborough and Burlingame. For a home near San Carlos, type a street address, an owner's name or a parcel number, and the viewer zooms to the match. For land near Hillsborough, a pop-up or side panel usually lists the owner of record, acreage on the tax roll, the parcel number and in many cases the last transfer.
A quick look at the area
Redwood City serves as the county seat, where most land records are kept. You'll also find Hillsborough, Belmont, Millbrae, and Burlingame, where town lots give way to larger tracts. About 726,353 people call San Mateo County home (Census estimate, 2023) across about 449 square miles. Landmarks such as Don Edwards San Francisco Bay National Wildlife Refuge make handy reference points on the map near Belmont.
What the map can't tell you
Acreage on the record is an estimate; just a licensed surveyor can set the real boundary on land around San Carlos. If you're looking near Hillsborough, owner names and values update on a schedule, so a deed recorded last month might lag behind.
Land on the county line
San Mateo County meets 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 Burlingame can be split across two assessors' files, so open the neighboring map as well. Closer to Hillsborough, our state page lists each neighboring county map for California.
Taking the map into the field
Most viewers work in a phone browser, handy when you're parked on a road near Millbrae, but coverage can be spotty out of town. A screenshot of the parcel near Burlingame with its ID helps when you meet an owner or agent.
When there's no plat
Rural land near Belmont that was never subdivided may have no plat at all; the deed and any recorded survey describe it instead.
When a plat changes
Lots near San Carlos can be combined or reconfigured by a replat, so check for later filings; street vacations show up in the records too.
Where Half Moon Bay fits in
Half Moon Bay sits in San Mateo County, California, which means parcel data comes from the county. Closer to Belmont, the municipality handles matters such as zoning, permits and utilities inside its limits, and the county still keeps the parcel and deed records. Land beyond the city limits near San Carlos often answers to county rules rather than the town's.
Recorded plat or GIS layer
If the tax map and plat differ near San Mateo, the recorded plat and a survey control.
Lots, blocks and easements
For property near Burlingame, the sheet usually includes lot and block numbers, dimensions and bearings, street rights-of-way and easements.
Ordering the Half Moon Bay plat map
On ground around Millbrae, many recorder offices offer an online index, otherwise call or visit with the reference; small fees are common.
Who handles what
Anything recorded against property around Burlingame come from the County Recorder, usually searchable by name or document number. Building or septic questions for a lot near San Carlos go to planning, building or health offices, depending on whether the land is inside town limits.
Legal descriptions in California
California is laid out under the Public Land Survey System, which means a tract near San Mateo is described by 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 Belmont odd-sized. Write down the legal description for the tract near Millbrae when you talk to a surveyor.
Deeds, plats and who keeps them
For anything that matters, request the recorded deed through the County Recorder; the parcel map near Belmont only summarizes it. Inherited tracts around San Carlos can go back through many deeds, so a title company earns its fee if money is changing hands.
Quick answers
How do I read lot and block in Half Moon Bay?
For property near Belmont, lot and block refer to a numbered lot within a block on a recorded subdivision plat.
Are old plats online in Half Moon Bay?
On ground around San Carlos, it varies; some offices have scanned older plats and some haven't, including older subdivisions.
What is a replat near Hillsborough?
Combining or splitting lots near Millbrae usually needs a recorded plat change; ask staff about the process.
How is a plat different from the parcel map near Hillsborough?
For a parcel near Burlingame, GIS parcels are tax drawings, and the recorded plat is the legal document; trust the plat when they differ.
How is land described in California deeds in Half Moon Bay?
Closer to Belmont, deeds use lot and block, metes and bounds or survey descriptions, and the parcel record often summarizes it.
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.