Get Garmin's " Basecamp " software, then go to http://gpsfiledepot.com and download the free Topo Maps there.

The Basecamp software will let you install the maps into your GPS and you can create routes with it and upload them to your Oregon. You can download tracks, routes, and waypoints from your Garmin into the Basecamp software to review your trip when you return.

Follow the instructions on the GPS File Depot site to install the maps into your Basecamp software, then follow the instructions on the Basecamp software to install the maps into your Oregon.
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