To read land survey property lines, you work between three things at once: the solid lines on the plat map that mark your boundaries, the bearing-and-distance labels that define each line’s direction and length, and the physical monuments the surveyor placed at your corners. The legend decodes the symbols, the scale bar and north arrow orient the drawing, and the written legal description backs up what the map shows. Once you can move between those pieces, you can trace your lot on paper and then find the same corners in the ground.
Get Oriented Before You Read Anything
Start at the title block, usually in a corner or across the top. It gives you the property address, the owner’s name, the licensed surveyor’s name and credentials, and the date the survey was performed. The date matters. A survey from twenty years ago may not show current structures, easements granted since then, or changes to neighboring lot lines.
Find the legend next, sometimes called the key. Surveyors don’t all use the same symbols, so a marking that means a utility line on one drawing can mean something else on another. Check the legend before you interpret anything on the page.
Then locate the north arrow and the scale bar. The arrow tells you orientation. The scale bar lets you measure a distance on the drawing with a ruler and convert it to real-world feet. Near the title block you’ll see the surveyor’s seal and signature, which confirm a licensed professional stands behind the work.
What the Lines and Symbols Mean
Solid lines on the plat map are your legal property boundaries. That’s the first thing to internalize, because everything else on the drawing sits in relation to those solid lines.
Dashed lines are usually easements. An easement gives someone else the right to use part of your property for a specific purpose, like running utility lines or reaching a neighboring lot. Knowing where easements fall matters before you build anything, because a structure placed inside an easement can be ordered removed at your expense.
Small circles, crosses, or triangles mark monuments. On paper these are just symbols; in the ground they are iron pins, rebar, iron pipes, or concrete markers, sometimes capped with brass or a plastic tag stamped with the surveyor’s license number.1Bureau of Land Management. BLM Module 3 Metes-and-Bounds Study Guide Other symbols will show structures like buildings and fences, natural features like streams or tree lines, and underground utilities like sewer or gas lines. The legend decodes all of them.
Setback Lines
Many surveys include setback lines, drawn as dashed or dotted lines running parallel to and inside your boundaries. Each one marks the minimum distance your local zoning code requires between the property line and any structure. If the survey shows a 25-foot front setback, nothing you build can sit closer than 25 feet from the front boundary. Setbacks vary by jurisdiction and zoning district, and violating them can bring fines or forced removal of the structure. ALTA/NSPS land title surveys include setback information when the client requests it and provides the zoning data.2National Society of Professional Surveyors. Minimum Standard Detail Requirements for ALTA/NSPS Land Title Surveys
The Monuments Are Legal Evidence
Those iron pins and concrete markers aren’t reference points you can move around. They are legal evidence of your boundaries. Removing or disturbing a survey monument is a crime in every state, typically a misdemeanor carrying fines and possible jail time, plus civil liability for the cost of having a surveyor re-establish the marker. The laws protect professionally placed permanent monuments, not temporary wooden stakes. If a landscaper, contractor, or neighbor displaces a pin, the expense of re-surveying falls on whoever disturbed it.
How to Read Bearings and Distances
Every boundary line on your survey carries two numbers: a distance and a bearing. Together they tell you exactly where that line goes.
Distances are given in feet, usually to two decimal places, and they are horizontal distances, as if measured on a perfectly flat surface. A boundary running up a hillside will show a shorter horizontal distance on the survey than you would measure walking it with a tape.
Bearings describe direction using four parts: a cardinal direction (N or S), an angle in degrees, minutes, and seconds, then a second cardinal direction (E or W). A bearing written as N 45°30’00” E means “start facing north, then rotate 45 degrees and 30 minutes toward the east.” The first letter tells you whether to face north or south. The angle tells you how far to rotate. The last letter tells you which way to rotate.
To trace your property’s shape, start at the point of beginning marked on the drawing and follow each call in sequence. Face the first bearing, travel the stated distance, turn to the next bearing, and repeat. When the last call brings you back to the start, you’ve traced the whole perimeter. The surveyor has already done this work; the plat map shows the result. The measurements and bearings let you verify any line you want to check.
Matching the Drawing to the Written Description
Your property also has a written legal description, either printed on the survey or referenced by it. It defines the same boundaries in words, and knowing which system your description uses helps you read the drawing.
Metes and Bounds
The oldest method, and still the most common for irregular parcels and properties in the original thirteen colonies. A metes-and-bounds description starts at a defined point of beginning and traces the perimeter through a series of calls, each with a bearing and a distance, until it closes back at the starting point.3Legal Information Institute. Metes and Bounds “Metes” are the distance measurements. “Bounds” are landmarks or features that define edges, such as a stone wall, creek, or road.1Bureau of Land Management. BLM Module 3 Metes-and-Bounds Study Guide If the description doesn’t close, meaning the final call doesn’t return to the starting point, that’s a red flag worth raising with a surveyor.
Lot and Block
In subdivisions, the description is much simpler. It identifies your property by lot number and block number within a named subdivision, then points to a plat book and page number where the detailed map is recorded with the county. Instead of tracing bearings yourself, you pull the recorded plat. This system dominates in urban and suburban areas where a developer subdivided a larger tract and filed the plat before selling individual lots.
Public Land Survey System
If your property sits in one of the roughly 30 states west of the Appalachians (plus a few southern states), the description may follow the Public Land Survey System. This federal grid divides land into six-mile-square townships, each subdivided into 36 one-mile-square sections of about 640 acres.4Bureau of Land Management. BLM Module 2 – The Public Land Survey System Study Guide Sections split further into quarter sections (160 acres), quarter-quarter sections (40 acres), and smaller parcels. A typical description reads something like “the NW 1/4 of the SW 1/4 of Section 12, Township 3 North, Range 2 West.” Read it backward: start with the section, then narrow to the specific quarter.5U.S. Geological Survey. Do US Topos and The National Map Have a Layer That Shows the Public Land Survey System (PLSS)?
Walking Your Property Lines
Reading the survey is only half the job. The rest is walking the property and locating the physical markers, and this is where most people get tripped up. Iron pins are often buried under a few inches of soil, hidden by vegetation, or knocked around by decades of landscaping.
Start with the corners. Look at your plat map and identify where the boundary lines intersect. Each intersection should have a monument. Use the survey’s measurements to estimate distances from a known landmark like the edge of a road or a building corner. A basic metal detector or magnetic locator will help you find buried iron pins and rebar. Without one, you’re probing blind with a screwdriver or thin rod, hoping to hit metal. Even surveyors use magnetic locators for pinpointing.
When you find a marker, don’t assume it’s in the right spot. Utility crews, landscapers, and construction work can knock pins out of position. If a found pin doesn’t align with the survey’s measurements, or if you can’t locate corners at all, hire a licensed surveyor. Trying to establish your own line based on a pin that may have shifted is how neighbor disputes start. A professional will compare what’s in the ground against your deed, the deeds of neighboring properties, and the recorded plat to verify each corner.
When the Paper and the Ground Don’t Match
Reading a survey sometimes reveals things that were invisible before: a neighbor’s fence sitting two feet onto your lot, your garage encroaching on an easement, or a shed straddling the line. The survey itself doesn’t fix any of it. It’s evidence, and how you use that evidence decides whether a problem stays small or grows expensive.
Talking to the neighbor is usually the first move. Most encroachments happen because neither party knew where the line actually fell, and showing the survey resolves many of them without lawyers. If you both agree on a fix, put it in writing as a boundary line agreement and record it with the county so it survives future sales. When a conversation doesn’t get there, mediation is the next step, and only after informal routes fail does a boundary lawsuit make sense. If the dispute is about who actually owns a piece of ground rather than about a physical encroachment, a quiet title action asks a court to determine ownership and eliminate other claims to that parcel.6Legal Information Institute. Quiet Title Action