I have a Garmin 64S GPS unit that I'd like to get a topographic basemap layer onto, so I'm not wandering with a blank screen while getting to my field sites for my research.

I'm using ArcMap 10.3.1, and I have a USGS topographic map that I'd like to download onto my GPS unit.

I've tried using Basecamp and Map Tiler software to get this topo onto my GPS via ArcMap, and I've also tried directly sticking it into a "CustomMaps" folder, but nothing has worked.

My GPS unit, which has the most recent software update, only accepts JPEGs for custom maps, which I've attempted to import to no avail.

I've called Garmin Customer Service, and they wanted me to georeference the .jpg via Google Earth, save it as a .kmz file, and then import it onto the GPS. Again, my GPS doesn't recognize .kmz files. I'm working with a GIS specialist, and we're both scratching our heads currently on how to do this.

Is it possible to take a topo from ArcMap and transfer it onto a GPS unit, or is that impossible?

4 Answers 4


Yes it is possible to create a custom basemap for a Garmin unit. It isn't straightforward or well documented. It definitely isn't supported by Garmin. There are a few ways of doing it, but the steps I used involve these software:

GPSMapEdit - import shapefiles into a Polish Map format file http://geopainting.com/

Cgpsmapper - convert the Polish Map Format file into Garmin IMG format http://www.cgpsmapper.com/

MapSetToolKit - Install the Garmin IMG format into the registry so that it's visible in BaseCamp https://sites.google.com/site/cypherman1/

BaseCamp - Garmin's software for loading maps onto a GPS receiver http://www.garmin.com/

NSIS - optional program to install the map on other people's computers. http://nsis.sourceforge.net/Main_Page

There is a decent site that has good resources on making these basemaps. GPS File Depot https://forums.gpsfiledepot.com/


Export it as tiff with world file and then use OkMap's MapTiling/Garmin Custom Maps utility to create a tiled kmz for uploading to your GPS. I believe OkMap is free, at least for this functionality, and they do ask for donations if you like it. The utility always asks if you want to overwrite the projection and do so, and then find their version of the projection to use.

QGIS has a Garmin Custom Map plugin which I can't vouch for.


There is a tool where you can export your active dataframe as a garmin custom map.

Its a toolbox with a python script that exports what you are seeing on your active data frame to a .kmz that is also readable by your GPS (the garmin webpage tells that your GPS should be able to).

The advantage of this toolbox (beside nothing necessary to install, free and a interesting python script) is that it honors the garmin built in restrictions. That are 1024x1024 Pixels and max 100 tiles in a kmz(some models can do more, but this is not documented but tested). Maybe that was why it did not work for you earlier.

Just put your topomap into arcmap and zoom to the extent needed. Start the tool from the toolbox (in the catalog where you downloaded it to) and put the 90 or something in the tilenumber. It will take quite long but will save a kmz that you copy into your CustomMaps folder (not sure about the garmin restrictions here about multiple custom maps and tile limit, so best try with only one kmz first). I think it depends on the area you are exporting what the outcome resoultion will look like (1 megapixel per tile times max. 100 tiles for your map). Used it this week to put a aerial image with some polygon overlays for a few hundred hectars onto a garmin. The resolution on the gps was as high as on the pc, so at least for not so large areas it is an option.



When you make the kmz the image tiles have to be in jpeg format. The easiest way to do it is to put your kmz on an SD card. Make a Garmin/CustomMaps directory and put the kmz in there. I tested this on a kmz I just made and used it on a 64S and it worked fine. Visible in BaseCamps also.

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