Installing Topo map

When your Oregon 300 is connected to your computer, are your maps saved as a disc image (dot IMG) file somewhere on the device (and NOT on a garmin preprogrammed card)?  On my Etrex Vista HCX (ancient I know), Edge 810 and Edge 830, all my Garmin Maps show up as such and I can copy them from one device (IE my 810) to another and gain access to them.

Thank you pkcryan. I managed to copy my IMG file to my Edge device. However, I could not find a way to unlock the map on this device. I'll try Garmin support if none else can help. Thanks!

is it in the main directory (for my computer it's " G:\Garmin ")? if they are anywhere else, they won't be visible.

In most cases, the maps end-up being locked to the device. The idea is copy protection. 

I understand copy protection but I bought de map separately from the device and I still have the unlock code for it.

Yes, this was the location where I put it. I emailed Garmin support and I'll update the forum if I hear from them.

The map will have locked to the device it was first installed on.

use basecamp for unlocking\managing maps

You can't transfer downloaded Garmin maps to a different device.  They are permanently mapped to the first device they are installed on.

Garmin maps bought on a SD Card can be transferred only buy moving the SD card to another suitable unit.  As the 830 does not have a SD card slot this can't be done.