I bought a Garmin Montana 650t at Christmas and I’ve used it a few times now for geocaching. One the thing I’ve found difficult is that the standard icons for geocaches are quite difficult to see against the backdrop of a colourful map. They are a little small, and have colours to close to those on the maps. The “Unknown” cache icon is particularly hard to see. So I began to search the internet for Garmin Custom Icons, how to make them and set them up. It was an interesting but ultimately successful journey.

Garmin Montana 650t


Google proved to be a double-edged sword. I found as many articles telling me it’s impossible as ones showing me how to do it. Many of the things I found were designed for users of the Garmin Oregon, which is an older and more mature product than my Montana. Some of the articles I found were in direct conflict with others.

Most of the articles I found concerned custom icons that could also be shared with Garmin’s BaseCamp PC tool for displaying caches. I experimented a bit, but eventually concluded that BaseCamp sees geocaches as a special type of waypoint. It’s therefore difficult to simply add another icon for it to use. You are stuck with a closed wooden chest, or an open chest full of shiny gold coins. Both of these appear on the screen at roughly the same size as Arkansas. Suffice to say my experiences of BaseCamp so far aren’t brilliant. Some more investigation is required before I figure out how to use it effectively.

Back at the plot, you may find this blog post useful if you are in the same situation. You may want to attempt the same thing. The post describes how I did it, and lists some pitfalls and heffalump traps.

I don’t go into any detail on the basics of how to create image files or move them around. I just describe the key activities to customize the icons on my Montana 650t. There are multiple sources of technical information on such matters and if you don’t already know how to move files between your PC and your GPSr then I wouldn’t even vaguely attempt this.

And I make no guarantees this will also work on your GPSr. I haven’t tried it out on any other device, because I haven’t got any others. It works on mine.

Enough of the waivers and general excuses. On with the clever bit.

What I Learned

To set a bit of background you should note the following points:

  • You can customize many aspects of the Montana’s “user” data, which includes all geocaches, maps, and also icons.
  • Custom icons do not replace the default ones in the Garmin’s storage system. The device uses a hierarchy of folders, and uses the custom folders before the default ones. You shouldn’t need to uninstall anything.
  • Most modern Garmins have internal flash memory (built into the device) and also use a MicroSD card installed somewhere in the battery recess. User data can go onto either of these.

Useful Resources

  • I spent a lot of time reading this one – http://garminmontanagpsr.wikispaces.com/Custom+Waypoint+Symbols – the names of folders and so on are all correct. The process for allocating custom icons in BaseCamp seems correct. It is a little thin on explaining how to replace the icons for different cache types on the GPSr device but it contained enough information to get me most of the way through the course, as it were.
  • This article got me excited – http://forums.gps.org.nz/viewtopic.php?f=3&t=7855 The icons used here look straightforward and clear (this is why the guy did it), and I could follow the thread fairly easily. It has a ZIP file of icons to download which I was able to use as a start point.

Making Some Icons

So what’s the process ? And “why doesn’t he just get on with it?” I hear you cry. Fair enough.

To start with you need a set of icons to replace on your GPSr. Here’s what to do.

  • Waypoint icons must be BitMap (.bmp) files with a colour depth of RGB 8-bits per channel. I started with the ones from the forums.gps.org.nz article listed above.
  • I also nicked a couple from the Groundspeak site because I wanted my Earthcaches to look like Earthcaches and my finds to look like smilies. Getting them from the Groundspeak site is not so easy and the Groundspeak files are quite low resolution.
  • Icons must be no larger than 32×32 pixels. In practice, 32 pixels is a big chunk of your screen. Mine are 16×16 or smaller.
  • They have to be named properly. The file to be shown for puzzle caches MUST be called “Unknown Cache.bmp”, for instance. If the custom names don’t match you’ll get a default icon.
  • There is no default icon for a “Geocache|Benchmark” type cache. However, geocaches of indistinct type use an icon called “Geocache.bmp”- If you download all your caches from PQs or from GSAK then they will all be listed as one of the “known” cache types. Use “Geocache.bmp” as a catch-all for anything that isn’t one of the supported (named below) types.
  • If you want a part of the image to be transparent on the GPSr you colour the relevant pixel in pure magenta (RGB 255,0,255 or #FF00FF). The GPSr ignores this colour.

Installing the Garmin Custom Icons

Once you have the icons ready you can install them on your device. You’ll be surprised how easy this actually is.

  • Connect your Garmin to your PC in mass storage mode (i.e. so the PC sees the GPSr just like any other drive/storage).
  • Create a folder called \Garmin\CustomSymbols on the Garmin’s internal memory – do NOT try to do this on your MicroSD card. When I did it on mine the GPS would not start up nor connect to the PC. I had to physically remove the MicroSD card from the GPSr and then insert into the PC and manually delete the icon files again.
  • Copy your icon .bmp files into this folder.
  • Disconnect the GPSr from the PC and switch it on.
  • That should be it !


And here’s a few pretty pictures showing how it looks.

Garmin Custom Icons - Aynho
Garmin Custom Icons - Brackley
Garmin Custom Icons - Silverstone

On the Aynho picture notice the maps also are showing the OS 1:25,000 scale you get if you invest in some of the BirdsEye Select maps from Garmin, rather than the TalkyToaster maps I’m using for the rest of the UK.

On the Silverstone picture you can see an example of the Benchmark icon for the YOSM there.

You should also notice tiny icons for “subsidiary” waypoints like parking, question to answer, reference points, stages of a multi, and trailhead.

Garmin Custom Icons - Steeple Claydon
Garmin Custom Icons - Earls Baton

And for these two you can see a good selection of icons on the Steeple Claydon picture, and an example of the Earthcache on the Earls Barton picture.

The file names for each icon are (no prizes for guessing which is used for what…):

  • Cache In Trash Out Event.bmp
  • Earthcache.bmp
  • Event Cache.bmp
  • Final Location.bmp
  • Geocache Found.bmp
  • Geocache.bmp
  • Letterbox Hybrid.bmp
  • Mega-Event Cache.bmp
  • Multi-cache.bmp
  • Parking Area.bmp
  • Project APE Cache.bmp
  • Question to Answer.bmp
  • Reference Point.bmp
  • Stages of a Multicache.bmp
  • Traditional Cache.bmp
  • Trailhead.bmp
  • Unknown Cache.bmp
  • Virtual Cache.bmp
  • Webcam Cache.bmp
  • Wherigo Cache.bmp