Since I got the Garmin Montana 650t at Christmas I’ve used it a few times for geocaching but one of the things I’ve been finding difficult is the icons it uses for displaying caches on the map. The main problems I found are that they seem to be a little small, and a little indistinct. The “Unknown” cache icon is particularly hard to see against a busy map background. So I thought I’d experiment a bit to see whether it’s possible to change the icons that it uses for each cache type.

The obvious first stopping off point was Google. In this instance, it proved to be a double-edged sword, as it often is. There are as many articles available that tell you it’s impossible as there are articles that show you how to do it. Many of the things I found were designed for users of the Garmin Oregon, an older and hence more mature product than my Montana. Some of the articles I found were in direct conflict with others. Also most of the articles I found were talking about custom icons that could also be shared with Garmin’s BaseCamp PC tool for displaying caches. I experimented a little bit with that but eventually concluded that BaseCamp sees geocaches as a different “kind” of waypoint to all other kinds, and therefore for some reason it doesn’t seem possible 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 which appear on the screen at roughly the same size as Arkansas. Suffice to say my experiences of BaseCamp so far aren’t brilliant, and so I don’t think I’m going to be using it much.

Back at the plot, this blog post is for the benefit of anyone else who may be in the same situation, and who may want to attempt the same thing. It describes how I did it, and more importantly, some things that definitely caused me a problem. In fact, I won’t go into any detail on the basics of how to create image files or move them around or whatever. Just the key bits I did to customize the icons on my Montana 650t. There are multiple sources of technical information on such matters and, quite frankly, if you don’t already know how to move files between your PC and your GPSr in mass storage mode then I wouldn’t even vaguely attempt this.

And I make no guarantees this will also work on your GPSr, and I haven’t tried it out on any other device (because I haven’t got any others). But it does work on mine.

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

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

  • The Montana allows various aspects of “user” data, which includes all your caches and maps, and also custom icons.
  • Custom icons do not replace the default ones in the Garmin’s storage system – it has a hierarchy of folders that it checks through, and the custom folders are checked before the default ones. So 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 – – 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 – – partly because the icons used look straightforward and clear (this is why the guy did it), and partly because it’s fairly clear. Plus you can download a ZIP file of his icons to use as a start point for your own, which is precisely what I did.

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

Making Some Icons

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

  • Waypoint icons must be stored as BitMap (.bmp) files with a colour depth of RGB 8-bits per channel. I started with the ones from the 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 – go into your list of finds, do a “View Source”, and then search the text for a particular cache type, and you should be able to see which tiny image it uses. Groundspeak renders them as low resolution .GIF files, so they need to be converted and re-saved in your image editor to RGB 8-bit per channel bitmap files.
  • They must be no larger than 32×32 pixels in size. In practice, 32 pixels is a big chunk of your screen. Mine are mainly 16×16 or smaller.
  • If you want them to be picked up by the GPSr unit as the icon for each specific cache type then they have to be named in a certain way. The file to be shown for puzzle caches MUST be called “Unknown Cache.bmp”, for instance. If the names for your custom icons are wrong then the GPSr will just use the default icon for that cache type.
  • For those of you in the UK who like to do a few YOSMs there is no default icon for a “Geocache|Benchmark” type cache – which is what the GPX file distributed by gives you. 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. So I fixed the problem by creating a picture of a benchmark (well, a mini-Stonehenge) and naming this “Geocache.bmp” – the YOSMs are the only items on the GPSr that are NOT one of the standard types, and hence the only waypoints that will pick up this icon. I don’t have icons for Lost & Found Event, Block Party or Groundspeak HQ either, but that’s not likely to cause me a problem any time soon.
  • Edit the icon files in your favourite picture editor.
  • 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. So if you wanted all your icons to be in bright magenta you’re scuppered.

Installing the 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 in called \CustomSymbols under the \Garmin folder 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. STOP PRESS…When I updated the package below to include the “Final location.bmp” file I experienced the same “failure”, only this time it was on the internal memory. As I was going through the “factory reset” process documents for the Montana it somehow righted itself and everything was once more sweetness and light. It is possible that my only failure was impatience, and I should just have waited longer while something on the device reset itself to accommodate the new icons. Maybe.
  • Copy your icon .bmp files into this folder.
  • Disconnect the GPSr from the PC and switch it on.
  • That should be it !

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

Cache Icons Aynho.jpg Cache Icons Brackley.jpg Cache Icons Silverstone.jpg

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.

Cache Icons Steeple Claydon.jpg Cache Icons Earls Barton.jpg

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

And here’s a download package of the icons I’m using now.

Custom Symbols Zip File

The file names for each icon need to be (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