Secret Garmin Map Function

The Secret Custom Map Function You Won’t Find in the Garmin Edge Manual

Garmin Edge 810

Several years ago, I volunteered to be a beta tester for Adventure Cycling. At the time, Adventure Cycling had converted their Northern Tier route map panels to custom maps and GPX files that could be displayed while navigating the route with my Garmin Edge 810.

Being able to view Adventure Cycling route map panels on my Garmin Edge while navigating turn by turn with the GPX files was a fantastic enhancement to Adventure Cycling’s already excellent maps. Evidently, Adventure Cycling didn’t fully agree with my assessment and a few years later I was an Adventure Cycling beta tester for the Route 66 on my phone with their new Bicycle Route Navigator app. While this app was another fantastic enhancement to their already great cycling maps, I prefer to use my GPS for navigation.

Fascinated by the first test with the GPS, I began to research how to display custom maps on my Garmin Edge (I am now using the Garmin Edge 1030). Although this capability is not documented in the Garmin Edge manual, it is easy to do.

Step 1: Save Map as JPG

To use a custom map on a compatible Garmin Edge the map must be in a JPG format. Unfortunately, most online maps are in PDF format and must be converted to a JPG. In most cases, the conversion is as simple as opening the PDF file and then saving it as JPG file. This can be done with several Adobe products such as Adobe Photoshop Elements or Adobe Acrobat Standard DC. However, if you don’t have software that can convert a PDF file, you can use GIMP a free software package at or other suitable software.

Step 2: Add Route to Google Earth

While this step is not necessary, it helps to precisely overlay the custom map on Google Earth in the next set. Many of the routes I use are available on RidewithGPS in the Google Earth .kml file format. I simply use the Export tab and click Google Earth (.kml) and open the file in Google Earth. However, if you don’t have a RidewithGPS, you can use GPX2KML a free online service at or other suitable software.

Step 3: Add Overlay to Google Earth

With the route in red on Google Earth, it will be easy to position the overlay to Google Earth. Use the add tab then select Image Overlay in Google Earth to add the JPG overlay. In the dialog box add the name of the overlay, provide the path for the JPG overlay and adjust the transparency of the overlay.

It can be a bit tricky positioning the overlay in Google Earth. However, with the route displayed in Google Earth from step 2, it is a simple task to match up the route with Google Earth and the overlay by using the green marks to adjust the corner, edges, center and rotation. It may also be necessary to adjust the transparency (in the New Image Overlay dialog) to a level that allows adequate viewing of the JPG and imagery beneath.

Once you are satisfied with the alignment of the source material, select “OK” on the New Image Overlay dialog box.

Step 4: Send Custom Map Panel to Garmin Edge
Garmin Edge Screen Shot of Custom Map

To send the newly created Custom Map to a Garmin Edge it must be saved to the device. To do this, right click the custom map in the Places section on sidebar on the left-hand of Google Earth, then select Save Place As and save the file in the KMZ format.

Now move or copy the KMZ file to your Garmin handheld device in the /Garmin/CustomMaps/ directory. Alternately, the file can be saved to a microSD card, in a /Garmin/CustomMaps/ directory. Once the Custom Map is saved to the device, it will appear on your Garmin Edge by default.

I’ve searched my Garmin Edge manual and I haven’t been able to find the instructions on how to create a Custom Map. While not specific to the Edge the following links can also be used as a guide on how to create a Custom Map:

Creating and Loading Custom Maps to an Outdoor Garmin Device.
Transfer Paper or Electronic Maps to Your Device

Ken Whittaker