How to Find Property Lines

1. Start with the plat map

The recorded plat map for your subdivision is the most important document for understanding your property lines. It shows the legal dimensions of every lot — frontage width, depth, and any irregular corners — along with easements and setback lines.

For Ada County, Idaho properties, you can search and download your plat map free at PlatMap. Search by your subdivision name or street address to pull up the recorded plat.

2. Read your deed

Your property deed contains a legal description that references the plat. It typically reads something like: "Lot 14, Block 3, Bridgetower Subdivision No. 5, as recorded in Book 97, Page 12156, Ada County, Idaho."

That book and page reference points directly to the recorded plat where the lot boundaries are drawn. Look up that plat and find your lot number to see the exact dimensions.

3. Look for physical monuments

Surveyors set physical monuments at property corners when a subdivision is platted. These are typically:

• ›Iron rebar stakes (usually ½" diameter) driven into the ground at corners
• ›Aluminum caps set in concrete at major corners and street intersections
• ›Plastic caps on rebar with the surveying firm's registration number stamped on top

Look for these at your corners — especially in undisturbed lawn areas near the street and at the back corners. They may be flush with the ground or a few inches below. A metal detector can help if they've been buried.

4. Check the county assessor's parcel viewer

Most county assessor websites offer a GIS parcel viewer that shows approximate property boundaries overlaid on aerial imagery. For Ada County, the assessor's parcel viewer lets you search by address and see your lot outline.

Important caveat: parcel viewer maps are approximate and not legally authoritative. They're useful for a general sense of where lines fall, but don't rely on them for fences, construction, or legal matters.

5. When to hire a licensed surveyor

For research and general reference, plat maps and online tools are usually enough. But there are situations where you need a licensed surveyor to physically locate and stake your boundaries:

• ›Building a fence, wall, or structure near a property line
• ›Adding an addition or accessory dwelling unit
• ›Resolving a boundary dispute with a neighbor
• ›Selling a property where the legal description is unclear
• ›The original monuments are missing or disturbed

A boundary survey in Ada County typically costs $500–$1,500 depending on lot size and complexity. The result is a staked survey with a Record of Survey filed with the county — you can find those on PlatMap too.

Quick reference: Idaho property line resources