Blog · October 14, 2026 · California
Using the Napa Plat Map
A recorded plat shows how land near Calistoga was divided into lots.
Main page: Napa 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.
Checking easements on a house in Napa? Start with the Napa plat map, because the recorded plat shows how the land was divided. What this city guide covers: where plats are filed, how a plat differs from a parcel map, and what to look for on the sheet, at least around Calistoga.
Getting started with the Napa plat map
For a subdivision near Yountville, the deed usually cites the plat; use it to request a copy.
The viewer Napa County publishes
Property in and around American Canyon can be looked up on the Napa County parcel viewer, which opens without registering. For property near St. Helena, put in a street address, an owner's name or a parcel number, and the matching parcel lights up. For a home near American Canyon, write down the parcel ID from that panel; every records desk in the county uses it to find the file.
Replats and vacations
Lots near Yountville can be combined or reconfigured by a replat, so check for later filings; street vacations show up in the records too.
Limits of the parcel data
Tax maps are drawn for assessment, not surveyed, so the edge of a yard near St. Helena may sit some distance off the line on screen. Closer to American Canyon, records update in batches, so a deed recorded last month might lag behind.
City limits and county records
Napa lies within Napa County, California, which means parcel data comes from the county. Napa is also the county seat, which puts the County Recorder close by. For property near St. Helena, the municipality handles matters such as zoning, permits and utilities for lots inside the boundary, but the county runs assessment and recording. Lots just outside the town limits out by American Canyon often follows county rules, not municipal ones.
Plat map vs. parcel map
The Napa County parcel viewer draws parcels for taxes, whereas the plat carries surveyed dimensions.
How land is described here
California is laid out under the Public Land Survey System, so rural legal descriptions near Calistoga cite section, township and range. A standard section is about one square mile, roughly 640 acres, with 36 sections to a township, though corrections make some sections near Calistoga odd-sized. Copy the legal description from the record for the parcel near Calistoga when you talk to a surveyor.
Napa County in a few facts
Napa holds the county offices, home to the main records offices. You'll also find Yountville, American Canyon, St. Helena, and Calistoga, where town lots give way to larger tracts. About 133,216 people live in Napa County (Census Bureau estimate, 2023) spread over roughly 748 square miles. Places such as Robert Louis Stevenson State Park make handy reference points on the map near St. Helena.
Where the recorded documents are
The map is an index, not the title: recorded deeds, subdivision plats and easements covering ground around American Canyon sit with the County Recorder. Long-held tracts around Yountville can go back through several deeds, so a title company earns its fee on a real sale.
Details on the Napa plat map
Out toward Calistoga, the sheet usually includes lot and block numbers, dimensions and bearings, street rights-of-way and easements.
Which office to call
For assessment questions about property around Yountville are handled by the County Assessor, since that office keeps the assessment data. Building or septic questions for a lot near St. Helena need the planning or permitting office, town or county, depending on location.
When there's no plat
Rural land near St. Helena that was never subdivided may have no plat at all; the deed and any recorded survey describe it instead.
Ordering the Napa plat map
If you're looking near Yountville, some counties put plat images online, while others require a visit or a request; small fees are common.
On site with the map
Most viewers work in a phone browser, handy when you're parked on a road near Calistoga, but coverage can be spotty out of town. A saved image of the lot near American Canyon and its lines keeps working without signal.
Neighboring parcel maps
Napa County borders Lake County, Solano County, Sonoma County, and Yolo County, and each of those keeps its own parcel map. Acreage along the edge near American Canyon may show up across two assessors' files, so look at the neighboring map as well. For a parcel near St. Helena, the Platbookmapper state page links every bordering county map across California.
Frequently asked
Where are historic plats for Napa?
Older plats near St. Helena may be on film or paper.
How do I read lot and block in Napa?
With a lot near Yountville, the description sends you to a specific recorded plat, so pull that plat for dimensions.
Is a plat map a survey in Napa?
In most cases, the plat near American Canyon is recorded, while the GIS layer is an approximation; trust the plat when they differ.
Do easements show on the plat near Calistoga?
It depends, but building on an easement near St. Helena is generally restricted; read the plat notes.
How do I save a parcel from the viewer around St. Helena?
Some viewers offer PDF export; include the record panel for the lot near American Canyon.
Open the official Napa 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.