A legal description is the precise, legally recognized way to identify a specific parcel of real property. An informal address like "123 Main Street, Oakland, CA" is not a legal description — it can change over time, duplicate in other cities, and is insufficient for a deed or deed of trust. Every deed, mortgage, and title insurance policy in California requires a formal legal description that will stand up in court.
There are three primary methods used in California: lot and block, metes and bounds, and the government rectangular survey system. California uses all three, depending on the region and age of the survey.
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The lot and block system (also called the recorded subdivision plat system) is the most common method used in California's cities and suburbs. When a developer subdivides land, they file a subdivision plat map with the county recorder. This map divides the land into numbered lots within numbered blocks, within a named subdivision.
A lot and block legal description looks like: > "Lot 14, Block 7, of the Greenwood Park Subdivision, as recorded in Book 22, Page 105 of Maps, in the Office of the County Recorder of Santa Clara County, State of California."
How it works in practice: When a Sunnyvale developer builds a 200-unit tract subdivision, they record the plat with Santa Clara County. Each lot gets a number. The legal description is simple, stable, and ties directly to a publicly recorded map anyone can look up. The buyer's escrow officer, title company, and lender all use this same reference.
Lot and block descriptions are reliable because:
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The metes and bounds method describes a parcel by tracing its boundary lines using directions (bearings) and distances, starting and ending at a point of beginning (POB).
A metes and bounds description typically begins with a monument or known landmark: > "Beginning at the iron pin set at the northwest corner of the intersection of Oak Street and Elm Avenue; thence North 89°30' East 150.00 feet; thence South 0°15' West 200.00 feet; thence South 89°30' West 150.00 feet; thence North 0°15' East 200.00 feet to the point of beginning."
California usage: Metes and bounds descriptions are common in rural areas, hillside properties, and older pre-subdivision parcels — especially in counties like Marin, Santa Cruz, and the Sierra Nevada foothills. They are also used when a parcel does not fit neatly into a platted subdivision grid.
Key concepts:
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The rectangular survey system (also called the Public Land Survey System or PLSS) was established by the federal government in 1785 for surveying public lands. California uses this system in its rural, desert, and agricultural regions — particularly in the Central Valley, eastern Sierra, and desert counties.
Key components:
California rural example: A 40-acre almond orchard in Fresno County might be described as: "The NW1/4 of the SW1/4 of Section 22, Township 14 South, Range 22 East, Mount Diablo Base and Meridian."
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Datum: A fixed reference point or surface from which elevations (heights) are measured. The standard in the U.S. is the National Geodetic Vertical Datum (NGVD). This matters for flood zone determinations, building elevation certificates, and grading permits — critical in flood-prone Bay Area communities and coastal zones.
Benchmark: A permanent, fixed point with a known elevation above the datum — often a brass disk set into a concrete post by the U.S. Geological Survey. Surveyors use benchmarks as starting points.
Monument: A physical object used to mark a boundary point — natural (rock outcrop, tree) or artificial (iron pin, concrete marker, railroad spike). Monuments are used in metes and bounds surveying and in marking subdivision lots.
Informal vs. formal descriptions on deeds: An informal description (street address, informal name) is acceptable for personal reference but is NOT sufficient on a deed. Deeds must use formal legal descriptions to ensure the specific parcel — and only that parcel — is conveyed. Title companies will reject deeds with only informal descriptions.
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Quiz Questions:
Q1. A title officer in San Jose is reviewing a deed for a single-family home in a 1990s residential subdivision. Which legal description method will she most likely find in the deed?
A) Government rectangular survey, because San Jose is in Santa Clara County B) Metes and bounds, because California was originally surveyed under Spanish land grants C) Lot and block, because the property is in a recorded subdivision plat D) Datum and benchmark, because the property is in a seismic zone
Answer: C — Modern residential subdivisions in California cities use the lot and block (recorded plat) system. The developer recorded a subdivision map with the county, and each lot carries a simple lot/block/subdivision reference. Metes and bounds is more common in rural or older unplatted parcels.
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Q2. A rural property in the Central Valley near Fresno is described as "The SE1/4 of the NW1/4 of Section 10, T12S, R21E, MDB&M." How many acres does this parcel contain?
A) 160 acres B) 80 acres C) 40 acres D) 640 acres
Answer: C — A full section = 640 acres. A quarter section (NW1/4) = 160 acres. A quarter of that quarter (SE1/4 of NW1/4) = 40 acres. Reading from smallest to largest: SE1/4 of NW1/4 of Section 10.
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Q3. A metes and bounds description begins at a "point of beginning" on the northeast corner of an intersection, then traces several bearings and distances, but fails to return to the starting point. What is the problem?
A) The description uses too many monuments and is therefore invalid B) The description does not "close," which means the boundaries are not legally complete C) The property must be re-surveyed using the government rectangular survey system D) The point of beginning is invalid unless it is a federally recorded benchmark
Answer: B — A metes and bounds description must form a closed polygon — the last course must return exactly to the point of beginning. An unclosed description creates ambiguity about where the boundary actually lies and cannot be used in a deed.
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Q4. Which of the following California principal meridians is used as the reference for properties in the Bay Area and Central Valley?
A) Humboldt Meridian B) San Bernardino Meridian C) Mount Diablo Meridian D) Sacramento Meridian
Answer: C — The Mount Diablo Meridian (MDB&M), based at the peak of Mount Diablo in Contra Costa County, is the reference for most of Northern and Central California, including the Bay Area and Central Valley. The Humboldt Meridian covers the far northwest, and the San Bernardino Meridian covers Southern California.
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Q5. A property seller tells her agent the address is "the old Johnson farm, corner of Highway 12 and Johnson Road, Sonoma County." The agent prepares a purchase agreement using only this description. What is the risk?
A) None — informal descriptions are sufficient in California purchase agreements B) The description is insufficient for a deed; title companies require a formal legal description C) The informal description is acceptable only if both parties sign an affidavit D) Informal descriptions are acceptable for offers but must be formalized only if the property exceeds $1 million
Answer: B — A street address or informal name is not a legal description and cannot be used in a deed or deed of trust. The correct legal description — lot and block, metes and bounds, or rectangular survey — must appear in all recorded instruments. Title companies will require this before insuring title.