Sunday, March 18, 2012

Garmin custom maps – Day 2

Garmin-custom-map Owners of the Garmin Colorado, Dakota and Oregon series got a nice surprise yesterday, when the company rolled out the ability to create a custom map image in Google Earth, opening the door to viewing aerial photos, USGS topos and park maps on your GPS.

I immediately downloaded a US Forest Service topo (which often have greater FS road detail than USGS topos), transferred a portion to my Oregon, and hit the trail. You can see the results in the image to the left.

Accuracy is completely related to how well you georeference the image, but I was pretty pleased with the results. The red line is a track of the trail created by someone else, so I can’t vouch for the accuracy of that, but my own track lined up well with the USFS trail on the map, and had me on the proper side of the creek, so I was pretty pleased with my first attempt. I’ll also note that the Oregon was in a mesh pocket on the back of my pack, not the ideal spot for reception. Admittedly, I wasn’t going that fast (15 MPH tops), but I noticed no problems with redraws. Others are reporting sluggish behavior for larger mapsets.

Tips for making custom Garmin maps

  • Use a DrawOrder of 50+ to keep the custom map on top of other imagery, as I did above. You’ll still be able to see waypoints, tracks, POIs, etc. This is ideal for topo maps.
  • Use a DrawOrder of less than 50 and contour lines, roads and depth contours present on the underlying Garmin map will show through. This may be better for park maps, marine charts and aerial photos.
  • This site has links for free raster imagery for each of the 50 United States. DRGs are topo maps, DOQQs are aerial photos. This is an older page, but enough links work to make it worth sharing.
  • If you need to convert from a particular file type to a .jpg (and don’t have software for it), search for an online file conversion service, or learn to use GIMP.
  • Scott at GPSFix had a great tips post yesterday, and has promised another today.

Custom Garmin map discussion threads

We’re all still learning about the process and limitations of this new tool. There are active discussions going on in the following forums:

More to come

Stay tuned. Over the next few days I’m expecting a lot of sharing of custom maps (this is already being done on the Garmin forum), tools for converting geo-referenced maps (eliminating the need to do this by hand), and information on using sources of .kmz files with images already posted online. Maybe some of you Google Earth ninjas can enlighten us on the latter in the comments section. And how about the rest of you? Have you tried this? How is it going?

About Rich Owings

Rich is the owner, editor and chief bottle-washer for GPS Tracklog. Connect with him on Twitter, Facebook or Google Plus.


  1. This great- brings Garmin into the Google Earth world. But will I ever be able to use this on my Garmin GPSMap 76CS? Would be great for geologic field work…
    -Tom Farr

  2. Rich Owings says:

    I don’t think they’ll ever be able to handle the raster imagery. I think Garmin will sell quite a few of the new units because of this feature.

  3. They can handle the raster map at walking speed only. I am using scanned raster map with my 60CSx.

  4. Yes, I use Moagu, do you mean won’t work on Colorado because I am using it in 60CSx.

  5. Rich Owings says:

    I’m saying these new type of raster maps (not Moagu) only work on the Colorado, Dakota and Oregon series.

  6. If you are looking for a simple tool to make Garmin Custom Maps from raster data this could be the one. Takes most images – png,tif.jpg and many calibration files – map, tfw, jpr etc and will produce a Garmin Custom Map in seconds.

    There’s a sample at

    Datums are converted if necessary and the map does not need to be aligned north-south.

  7. Jim Kaczmark says:

    When selecting the link to “US Forest Service Topo” above, the link is now broken, receiving a “Error 404 – File Not Found”. I tried selecting the “Raster Data Gateway” from this same error page, but receive the same error again. (I’m very new to my GPS I custom maps, but am assuming I needed the rastor file.) Is there another download source for US Forest Service topo map downloads so I can load them onto my Garmin Oregon 550?

    Thanks in advance.

  8. Recently OkMap freeware software include a feature to generate automatically compatible Garmin custom maps (kmz format).
    The map calibration is sophisticated because OkMap uses different type of projection and several datums.
    This new feature includes map tiling from and to different image file formats (including from ECW map files).
    It’s possible select KML extensions 2.2 (if GPS supports them), the JPEG quality, KML transparency, draw order, ecc..
    You can select the tiles to generate in output.
    This feature support also not north oriented maps.
    OkMap include a Google maps server to download maps from Google, OpenStreetMap, MyTopo, DOCQ, ecc..
    These two features combined together may be very useful.

    • Thanks. I saw that and will have to try it. This seems to be a trend — mapping software supporting Garmin custom maps. We’ve now got OkMap, TopoFusion and Terrain Navigator Pro doing it.

Speak Your Mind

Tell us what you're thinking...
and oh, if you want a pic to show with your comment, go get a gravatar!


− one = 2