📍 1. GPS Accuracy vs. Legal Accuracy

Most phones, tablets, and recreational GPS units are accurate to about 10–20 feet under ideal conditions. Even professional mapping apps like Google Earth use imagery aligned to satellite data that can shift by several feet or more — especially in rural or sloped areas.

A legal boundary survey, by comparison, must achieve accuracy within hundredths of a foot (centimeter-level precision). That difference is the gap between roughly knowing where a line is and proving it legally.

🛰️ 2. Why Property Lines Require a Licensed Surveyor

In Arizona, only a Registered Land Surveyor (RLS) licensed by the Arizona Board of Technical Registration (AZBTR) can officially establish or mark property boundaries.

Using GPS or online maps to place fences or structures without a certified survey can result in:

• ❌ Encroachments onto neighboring property
• ❌ Boundary or easement disputes
• ❌ Permit rejections or title issues during sale

🗺️ 3. What Google Maps *Can* Be Used For

Apps like Google Maps, Gaia GPS, or OnX are great for general orientation — finding approximate lot shapes, travel routes, or nearby features — but not for staking or construction layout. They’re tools for visualization, not verification.

⚖️ 4. Arizona Law and Survey Standards

Boundary evidence and monumentation in Arizona are governed by Arizona Administrative Code R4-30, which requires that all boundary surveys be performed, sealed, and recorded by a licensed RLS. Only these surveys are accepted by county and municipal agencies for permits, plats, and legal filings.

💡 5. The Safe Way to Locate Property Lines

If you want to mark your boundaries, hire a licensed surveyor to perform a Boundary Survey or Lot Survey. The surveyor will:

• 🔹 Research your recorded deeds and plats
• 🔹 Recover or set corner monuments
• 🔹 Provide a signed survey drawing for your records

For most residential properties in Arizona, this typically costs $650–$1,500 depending on size and accessibility.