How to use ArcMap to create Garmin custom maps

ArcGIS includes a Map to KML tool that will create a KML file from an existing map document. The exported KMZ file will open in GoogleEarth or other KML file viewers, but the default image format it creates is not compatible with Garmin GPS units.

This video illustrates the export process, plus some quick edits you can make to create a Garmin-compatible KML file that will work on most recent map-enabled Garmin GPS units, such as the Dakota, Oregon, Colorado, Map78, map 62, and the eTrex 20 & 30. In addition to ArcMap, you should also have access to a text editor such as Notepad, an image editor such as the GIMP or ImageJ, and Google Earth.

To view your exported map on your Garmin GPS, you will need to ensure custom maps are enabled (they are by default). This process will vary slightly depending on the unit you have; it should be similar to the following (steps from a GPSMap 78):
MENU > Setup > Map > Map information / Select Map and scroll to Custom Maps. If Enabled – Custom Maps is shown, you should be all set. If Disabled – Custom Maps is shown, press ENTER, select Enable, and press ENTER again to toggle the setting. Press QUIT several times to exit Setup and select the map screen.

You should now be able to pan to the location for your map and view it on the GPS screen. You may need to zoom in to have the map appear.

If you are a QGIS user, open Plugins > Manage and Install Plugins… and search for GarminCustomMap. This plugin will export the current map canvas to a Garmin-compatible KMZ file.

*Update 6/20/2016

An ArcGIS tool has been developed to create Garmin custom maps directly. Details may be found at 

Workflow outline for ArcGIS

  1. Set up map with layers symbolized as you like them; save MXD
  2. Create separate layer to denote map export extent
  3. Run Map to KML tool. Be sure to set Extent Properties to use the layer from 2. and the Data Content Properties to create a single composite image
  4. Use 7zip to extract the contents of the resulting KMZ file to a folder
  5. Convert the Composite.png PNG image to a JPG. Delete the original PNG
  6. Edit the doc.kml file by dropping it on a Notepad window. Change the extension on Composite.png to Composite.jpg and save the file and quit Notepad
  7. Select the two files (Composite.png and Doc.kml), right-click, and save to a new zip file
  8. Change the file extension from .zip to .kmz
  9. Copy the kmz file to your GPS unit > Garmin > CustomMaps folder
  10. If you don’t see your map, ensure your unit is configured to display custom maps

DNRGarmin and newer Garmin GPS models

Newer versions of Garmin GPS units (Colorado, Oregon) do not connect to your computer in the same fashion as the older models (GPSMap 76, GPSMap 62). These newer Garmins mount their internal storage as a drive letter, e.g., “E”, similar to mounting a flash drive or external hard drive.

To download data from one of these units to DNRGarmin, Go to File->Load From->File… Select “GPX” as the file type and navigate to your GPS’s drive (the drive letter that shows up when you plug in your device). You’ll find a folder housing a bunch of GPX files with time-stamp names. Those contain your waypoints. Select one to load it into DNRGarmin and then save out to a new file (text file for backup or shapefile for use with ArcGIS).

To upload from DNRGarmin to the GPS, go to File–>Save To–>File… and save a GPX file to the same location on your GPS as that you downloaded from above.

Transferring track history points should work in the ‘normal’ DNRGarmin fashion.

Note I do not have access to one of these newer units – these instructions are written from “help me” postings I have found online. If you have an Oregon or Colorado unit and would like help using DNRGarmin, I will be happy to do so (and can then verify these instructions).

mdhyslop at or 7-2308