As Google continues to make it harder for applications to share data, you may have to move your offline maps and GPX save location to a MyTrails-specific folder rather than the traditional /sdcard/MyTrails.

Several users have reported that using a folder like android/media/com.frogsparks.mytrails (inside the main device storage, presumably also on a removable storage) works.

When selecting the offline map location, use the “device” button in the top-right corner to switch to that directory directly:

If you’re not using offline maps (only GPX saved tracks), you can probably stick with your usual save location, but you need to switch to the standard Android file picker (disable Use internal file picker in MyTrails > Preferences > Other).

For more general info, see this older post.

In order to make it easier to manage offline maps, I usually recommend creating separate offline maps for separate geographical areas.

However, this makes it necessary to switch maps when looking at different parts of the map. Unless you chain maps together using the fallback map feature.

Picking a fallback map

Most maps, and particularly offline maps, support setting a fallback map. To do so, tap the name of the map in the Map manager, and then the Select… button in the Fallback map section. You can then pick the fallback map, which will be used where the main map does not provide a tile.

Using this system, you can chain maps together:

• set the fallback map for map A to map B
• set the fallback map for map B to map C
• etc.
• in the main MyTrails view, select map A, and MyTrails will automatically display map B or C in areas not covered by map A.

A, B and C do not need to all be offline maps. in fact, it may be useful to select an online map as the last map in the chain, so that there is always something to display. This is what MyTrails does when you create an offline map and check the Let MyTrails download missing tiles option.

Create offline map with fallback

So you’ve downloaded a bunch of maps offline, and MyTrails placed them on your phone’s internal storage?

MyTrails doesn’t attempt to help do this, because moving large amounts of data around is difficult to do in a compatible and safe way. So please follow this guide:

1. in MyTrails > Preferences > Other (storage), set the New offline maps location to your external SD card (you can use the SD card icon if you see one, or navigate to the external SD card if not)
   
2. use an Android file manager such as ES Explorer to move the contents of /sdcard/MyTrails/Offline to the location you selected above
   if this is not possible (Android 4.4 and later, unless rooted), transferring the files using a computer is required
3. in MyTrails > Maps, tap on each of the offline maps you created and adjust its location
   

If step 3 sounds too tedious, you can skip it; the next time MyTrails starts (you can stop it manually to make this happen sooner), it will automatically regenerate the map definitions for you (but it leaves the old ones, you’ll need to hide them in MyTrails > Maps, or delete them by long-pressing the map names and selecting Delete – make sure not to delete the map data, just the definition!).

If this does not succeed, please use the reset offline hidden option.