Online Tools for Finding Arizona Property Lines
Several free online tools can help Arizona property owners get a general sense of where their parcel boundaries are. These tools draw on recorded plat and deed data and are useful for initial research. None of them replace a licensed survey when you need a legally precise result.
Maricopa County Assessor GIS Viewer
The Maricopa County Assessor operates a map viewer at maps.maricopa.gov that lets you search by address or parcel number and view parcel boundaries overlaid on aerial imagery. You can see your lot shape, adjacent parcels, and basic parcel information including the assessor parcel number (APN), which you will need when contacting a surveyor for a quote.
The Maricopa viewer is one of the more capable county GIS tools in Arizona. It includes layers for flood zones, zoning, and recorded easements in some areas. But the parcel layer is based on recorded plat data and can have alignment discrepancies of several feet relative to real-world ground positions. It is a reference tool, not a survey substitute.
Pima County Online Mapping Tool
Pima County's GIS portal, accessible through gis.pima.gov and linked from the Pima County Assessor's website at assessor.pima.gov, provides parcel boundary data for properties in the Tucson area and unincorporated Pima County. You can search by address or APN and export parcel information. Like other county GIS tools, it reflects recorded plat data and should not be used as a legal reference for boundary decisions.
Arizona State Land Department Parcel Viewer
The Arizona State Land Department maintains a parcel viewer at land.az.gov that shows State Trust Land boundaries alongside private parcels. This tool is particularly useful if your property is adjacent to or near State Trust Land, which covers roughly 9.2 million acres across Arizona. The viewer helps you understand where the state boundary sits relative to your parcel, though again, it is not a replacement for a licensed survey if the exact line matters.
Other County Assessor Tools
Most Arizona counties have some form of online assessor or GIS mapping for property lookups. Quality and detail vary widely:
- Yavapai County: Yavapai County Assessor's office provides a property lookup with parcel mapping at assessor.yavapai.us
- Mohave County: Mohave County Assessor at mcassessor.com provides parcel search and limited mapping
- Cochise County: Cochise County Assessor at assessor.cochise.az.gov includes parcel lookup and GIS layers
- Pinal County: Pinal County Assessor at assessor.pinalcountyaz.gov provides property search with parcel data
For rural counties, GIS data may be less detailed or less current than in Maricopa or Pima County. If you are working with rural land, the county recorder's recorded plat maps may be more reliable than the GIS viewer.
Finding Your Plat Map
If your property is within a recorded subdivision, a plat map was filed with the county recorder when the subdivision was created. The plat shows each lot's dimensions, the street layout, any recorded easements, and the lot-and-block designation used in the legal description.
To find your plat in Maricopa County, go to the Maricopa County Recorder's online portal and search for the subdivision name or book and page number from your deed. In Pima County, use the Pima County Recorder's recorded documents search and search by subdivision name.
The plat tells you the designed dimensions of your lot. It does not tell you where the corners physically are on the ground today, because monuments may have been disturbed or the original survey had small errors. The plat is a starting point, not a ground truth.
What Survey Monuments Look Like in Arizona
If you want to physically find your property corners, knowing what to look for is the first step.
Iron Pins and Rebar
The most common type of monument in Arizona residential subdivisions is an iron rebar pin, typically half an inch in diameter and 18 to 24 inches long, driven vertically into the ground at the corner. The pin usually has an aluminum or plastic cap crimped or glued to the top, stamped with the surveyor's license number, company name, or a notation like “P.L.S.” (Professional Land Surveyor). The cap helps identify who set the monument and when.
Concrete Monuments
In some older Arizona subdivisions and in rural areas, corners are marked with concrete posts set flush with or slightly above the ground. These are more durable than iron pins in stable soil but can be harder to find if overgrown or covered. Some have a brass cap set in the top surface.
GLO Brass Caps
In rural Arizona, original U.S. General Land Office (GLO) survey monuments from the late 1800s may still be present. These are brass caps set in concrete or drill holes in bedrock, stamped with township, range, and section designations. They mark the corners of the PLSS grid sections that underlie all rural land descriptions. Finding one near your property is useful for a surveyor but should not be confused with your actual parcel corner unless your deed specifically references it.
Monuments in Desert Terrain
In sandy desert terrain, iron pins can be buried by wind-blown sand or disturbed by utility trenching and irrigation work. Some surveyors in Arizona set monuments slightly below grade in desert areas specifically to reduce disturbance, and mark them with a surface witness such as a mound of gravel or a PVC pipe cap. Look carefully before concluding that no monument exists.
Using a Metal Detector to Find Pins
A basic metal detector can help locate buried iron pins if you have a general sense of where the corner should be based on your plat dimensions. This is a legitimate self-help step before calling a surveyor. If the detector finds a pin, confirm the cap markings match a licensed Arizona surveyor's registration number before relying on it. If you find something that appears to be a pin but has no cap or is unlabeled, do not assume it is an official monument.
When Online Tools and Self-Search Are Not Enough
Online GIS tools and physical searches for monuments are good starting points. They become insufficient when:
- You cannot find existing monuments and need legally recognized corners set
- Your neighbor disputes where the property line is
- You need the line for a fence, structure, or permitted improvement where an error would create legal exposure
- The parcel is described by metes and bounds rather than a plat, making self-research unreliable
- Your property is adjacent to a wash, drainage easement, or State Trust Land boundary where the precise location matters
- You are buying or selling the property and want to confirm what is actually being transferred
In any of these situations, a licensed Arizona Professional Land Surveyor is the only person who can give you a legally reliable answer. The survey may confirm what you already suspected, or it may reveal a discrepancy that needs to be resolved before you proceed.
Browse our directory to find a licensed Arizona land surveyor in your county. Whether you are in Maricopa, Pima, Yavapai, Coconino, or anywhere else in the state, our directory lists firms organized by location and service area.