Some Garmin GPS receivers write user date (waypoints, routes and tracks) to SD card files. The folder structure is normally　

Garmin -> UserData -> UserData.ADM

　　　　　　　　　　 -> GarminDevice.xml

To transfer data to/from the GPS using GPS Utility, first initialize the SD card by following the procedure in your Garmin GPS manual. This will write the correct folder structure to your SD card. Transfer the SD card to a suitable card reader device on your computer.

To transfer data from the card to GPS Utility open the 'UserData.ADM' file using GPS|Download All...

To transfer data to the SD card from GPS Utility, Upload the data to the 'UserData' folder on the SD Card as the file 'UserData.ADM'. If the filename is not correct then GPSU will ask you to confirm the filename.