Property Line Maps

At Property Line Maps we produce online maps for your cell phone or computer that show your approximate property lines on the Google aerial and on the USGS topographic map. Each client also receives a GPX file with approximate corner coordinates that can be loaded into many handheld GPS units.

If you are reading this on a cell phone or small tablet, then please visit for all the details and to place an order. But if you are reading this on a large tablet or other large screen then we recommend you visit to learn more.

After we process your order, open the email we send you and click or tap the link to open your online map on almost any device from cell phones to desktop computers. If you open your online map with a cell phone then you can turn on a geolocation feature and see where you are as you walk around your land. No cell connection on your land? No worries! We show you how to use your cell phone offline.

Or instead of using a cell phone you can load the GPX file we send you into many Garmin GPS units and find survey stakes or find approximate property lines.

Most single parcels cost $49.98 and include the online map link and GPX file.

Although the property corner coordinates and property lines we produce are approximate, they are still the most accurate coordinates you can get without hiring a surveyor. But if you need to know exactly where your property corners and lines are located, then you will need to hire a surveyor.

Property Line Maps on Facebook

Gmap4 Enhanced Google Maps

Gmap4 is an enhanced Google map viewer that is free for non-commercial use. It is used by people that enjoy a wide range of outdoor activities. Click a link and the map opens in the browser on most devices from cell phones to desktop computers.

Cell phone and other mobile users see a touch-friendly interface and can turn on geolocation.

You can view Google aerials, high resolution USGS topographic maps plus other basemaps. You can display GPX files and KML/KMZ files. You can also display user-specified GIS data (ArcGIS and WMS) including GIS attribute data.

The Gmap4 homepage has a FAQ for new users, examples, a 'Quick Start' pdf file (on the Help page) and more.

Gmap4 on Facebook


FindMeSAR displays your GPS coordinates and accuracy value

This browser app is intended for smartphones. It will also work well on tablets that have a GPS chip.

In about a minute or less your coordinates will be shown usually with an accuracy of about 5 meters (~16 1/2 feet).

The "Next Format" button will scroll through four coordinate formats with a different colored screen for each one.

FindMeSAR works online and offline. For more information on offline use please see 911 Wireless Location Accuracy and click "Read FindMe part 3". This webpage also has other useful information and shows how a 911 dispatcher can help a wireless caller use FindMeSAR to provide accurate GPS coordinates for their location.

For the most accurate coordinates you should be outside with a reasonably good view of the sky. Android users should set their 'location method' to 'GPS only' (also called 'Device only').


Test your cell phone location accuracy
FindMePro is a browser app that anyone can use to find out which settings on their cell phone or tablet produce the most accurate latitude longitude coordinates showing their location. I produced this browser app after discovering that my iPhone 4s sometimes produces coordinates with a good accuracy value but which in reality are wrong by several miles.

While you can try FindMePro on desktop and laptop computers, typically the accuracy will be very poor. FindMePro is intended to run in browsers on cell phones and tablets.

This app lets you:
1. Ask your browser to keep giving you your location coordinates while improving the accuracy.
2. Display the details for each set of coordinates on your screen.
3. Display each location on the Google aerial. Smaller circles indicate more accurate coordinates than bigger circles.
4. Adjust certain settings that are used by the app. For example, you could ask your browser to give you just a single coordinate instead of a stream of coordinates.

Open FindMePro

Typically when you tell this app to start collecting data the first locations returned are not very accurate and result in big circles on the map. Fairly quickly the accuracy should improve until the circles have about a 5 meter radius.

About button
The app’s “About” button has more information on how you can test your cell phone to find out which settings on your phone produce the best and worst coordinate data.

Crowd sourced buttons
The two "Crowd Sourced" buttons have information on sharing your results so we all learn how to get the most accurate coordinates from our phones and how to recognize bad coordinates.

Two reasons for poor coordinate accuracy
First, certain settings on your phone can influence the accuracy of the coordinates your phone produces. Please read the text under the "About" button for suggestions on which settings you might want to test. Second, FindMePro tells your browser to only report coordinates for your current location and to *not* report any cached coordinates for any prior location. Some (all?) browsers ignore this instruction and sometimes report cached coordinates that can be wrong by several miles. For more information tap the "Crowd Sourced Results" button.

How to compare coordinates produced by other apps
1. Use FindMePro to collect coordinate data and display the map.
2. Tap Menu ==> Search
3. Enter coordinates from any other app into search bar at the top of the screen.
4. Tap Go
The map will center at the coordinate you enter. You can see how, that location compares to the green circles (last three coordinates) produced by FindMePro.

Offline use
Currently FindMePro only works if you are online. The browser technology needed to implement offline use is currently undergoing a major change (from 'appcache' to 'service workers'). After most browsers implement this new technology and it is stable, then support for offline use will be added to FindMePro.

Cascadia Rising and USNG

Cascadia Rising assumes a 9.0 earthquake takes place just off the Washington, Oregon and northern California coast. In June 2016 many government agencies at all levels will conduct an exercise on responding to such a mega disaster.

U.S. National Grid (USNG) is the coordinate system adopted by FEMA and other federal agencies as a standard that they will use during a disaster response.

Chaos over location of people, places and events is what you get after a disaster when responders from near and far are not all using the same coordinate system and therefore *not* speaking a common "language of location". Although they likely know better, the state and local agencies have failed to agree that they will all use the USNG coordinate system during the exercise.