Blog · October 14, 2026 · California
Using the San Rafael Plat Map
A recorded plat shows how land near Ross was divided into lots.
Main page: Marin County, CA GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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When a listing near Mill Valley mentions a lot number, look up the San Rafael plat map it refers to. In this San Rafael guide: where to request a copy, plat versus tax map, and what to look for on the sheet.
Getting started with the San Rafael plat map
For land around San Anselmo, look for the plat book reference on the parcel record; use it to request a copy.
Opening the official parcel viewer
Begin with the Marin County parcel viewer; it maps each tax parcel from Mill Valley to Tiburon. If the land is near Corte Madera, enter a street address, an owner's name or a parcel number, and the viewer zooms to the match. For acreage around San Anselmo, the parcel card normally shows the owner of record, acreage on the tax roll, the parcel number and in many cases the last transfer.
Taking the map into the field
Most viewers work in a phone browser, useful out on a road near San Anselmo, though signal can drop in rural spots. A printout of the tract near Tiburon keeps working without signal.
Where San Rafael fits in
San Rafael sits in Marin County, California, so its parcels are on the county's map. San Rafael is also the county seat, handy when you need recorded documents. Closer to Ross, city or town hall handles things like zoning, permits and utilities for lots inside the boundary, and the county still keeps the parcel and deed records. Lots just outside the city limits near Ross often answers to county rules, not municipal ones.
Neighboring parcel maps
Marin County borders Contra Costa County, San Francisco County, Solano County, and Sonoma County, and each of those keeps its own parcel map. Acreage along the edge near Corte Madera can be split in two county records, so check the adjacent map before you assume the acreage. With a lot near Corte Madera, our state page links each neighboring county map across California.
Recorded plat or GIS layer
The tax map on the Marin County parcel viewer is a summary, whereas the plat carries surveyed dimensions.
Who handles what
For assessment questions about property around San Anselmo go to the County Assessor, the office behind the parcel record. Zoning, permits and septic questions near Tiburon are for the local planning and health departments, town or county, depending on location.
Lots, blocks and easements
Utility or drainage strips on a lot in San Rafael limit where you can build or fence; read the notes on the sheet.
Deeds, plats and who keeps them
Before you sign anything, request the recorded deed through the County Recorder; the parcel line is a drawing of it, whether the land is near Ross or elsewhere in the county. If the land is near Corte Madera, have ready the book and page shown in the record panel and the lookup takes minutes.
Metes and bounds instead
Rural land near Tiburon that was never subdivided may have no plat at all; the deed and any recorded survey describe it instead.
When a plat changes
An amended plat may change lots around Corte Madera, search the index for replats of the same subdivision; vacated streets or alleys also get recorded.
Online indexes and office visits
In and around San Anselmo, many recorder offices offer an online index, otherwise call or visit with the reference; small fees are common.
How land is described here
California uses the Public Land Survey System, so deeds around San Anselmo reference sections and townships. A standard section is about one square mile, roughly 640 acres, and a township holds 36 of them, though sections near Tiburon can be irregular. Keep the legal description for land near Tiburon when you talk to a surveyor.
A quick look at the area
San Rafael holds the county offices, home to the main records offices. Smaller places on the map include Larkspur, Ross, Corte Madera, and San Anselmo, each with its own cluster of lots. About 254,407 people live in Marin County (Census estimate, 2023) on roughly 520 square miles. Features like San Pablo Bay, San Francisco Bay, and Golden Gate National Recreation Area are easy to spot when you zoom out from San Anselmo.
A word on accuracy
Listed acreage is an estimate; only a licensed surveyor can set the real boundary on land around Corte Madera. For a parcel near Tiburon, owner names and values update on a schedule, so a deed recorded last month might lag behind.
Frequently asked
Where are historic plats for San Rafael?
Older plats near Ross may be on film or paper, including older subdivisions.
Who has recorded plats for land near Ross?
Short answer: recorded plats near Corte Madera are filed with the County Recorder; small copy fees are common.
What is a replat near Mill Valley?
It depends, but lot splits in San Rafael go through the planning office; ask staff about the process.
What do the dashed lines on a plat mean in San Rafael?
In and around Corte Madera, dashed lines often mark easements or building lines, so check before you build.
Where do I find the parcel number for land near Mill Valley?
Every office uses it to pull the same file for land near Ross; you'll see it in the viewer and on tax statements.
Open the official Marin 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.