OpenStreetMaps for Garmin eTrex 10

In my previous post I explained how to install topographic maps into Garmin eTrex 10 GPS navigator.

Unfortunately, it seems like detailed topographic maps are not available everywhere, for free anyway.

Therefore, I felt obligated to present an alternative way to get Garmin eTrex 10 compatible maps.

The first, an probably the best place to start looking for maps are the openstreetmap.org pages.

Openstreetmaps (I call them OS-maps from now on) are somewhat motoring oriented, and they do not tell you much about the terrain, but most of the roads, trails, waterways, and such are marked pretty well. The coverage varies from place to place, and one has to be aware of that, but, as I have mentioned before, any map is better than the original Garmin World Wide Base Map.

A good thing about the limited details of the OS-maps is that one can easily fit a map covering thousands of square kilometers (or miles) into 8 MB storage space of eTrex 10.

Well then, how to start?

First, go to the openstreetmap.org page. Pan, zoom, and study the map. (The level of details on the map will be the same on your Garmin eTrex 10). When you have found the area you are interested in, click the “Export” button on top of the screen. Now, if your map area is small enough (openstreetmaps lets you download about 35X35 km (22X22 miles) maps), just click the blue and white “export” button to download the map. If your map is too large, click “Manually select a different area”, and resize your area till the blue and white “export” button appears.

If you are looking for larger maps to download, scroll down a little bit, and click “Planet OSM”. From Planet OSM, you can find several downloading options, but for eTrex 10 maps, I recommend clicking “BBBike.org”. From the BBBike.org, you can download premade maps, or choose your own by clicking “select your own region”. From there, you can pan and zoom to your favorite area, and select the size and shape of your map. Wonderful thing about the BBBike.org, is that when you are selecting your map area, you can see the size of the package at the left side of the window (remember the max limit of 8 MB for eTrex 10. The size of the map decreases a little bit during the further processing, but don’t try to download any GB size maps).

Once you have selected the map area, choose the file format. (I have used “OSM XML 7z (xz)”).

Then BBBike.org wants your e-mail address (I have not had any junk mail or any other trouble after giving my address.), and after couple of minutes, you will receive an e-mail with links to download your new map. Then extract the zip file, and you are ready for the next step.

Now, you should have a xxxxxxx.OSM file in your computer. To convert the OSM file to Garmin accepted IMG file, there are several free programs available. My favorite is the mkgmap, which can be found from mkgmap.org.uk or from LINUX repositories. As a Linux user, I have installed two programs, “mkgmap”, which is the converter program itself, and “mkgmapgui”, which is a graphical user interface for the mkgmap.

To operate the mkgmap on Linux, type “mkgmapgui” to the terminal window, and click “enter”.

In an appearing, self-explanatory window, select your newly downloaded OSM file, give it a random number (this is probably for some more complicated map projects, but for some reason, the program asks for a number), and click “Convert”. Next, the program asks you for the saving location and the name for your new IMG file. Give them, click “Save”, and in few seconds you have your map in Garmin compatible IMG format.

The only remaining thing to do is to load your new map into your Garmin eTrex 10, as instructed here.

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