Just go to
http://www.gpsfiledepot.com/ and browse the maps to see if any will fit your needs (sorry, I've never heard of Mt. Yale
)
Click on any that interest you and read all the information supplied by the author. It should explain how to download and install the map. The download is extremely simple, just a couple mouse-clicks. There are also excellent tutorials on this site to help. If you need more help, post your questions here.
Downloading and installing maps from this site will have no effect on your pre-loaded Garmin Topo's. Those are stored in a special file. HOWEVER, take the time now to do a complete backup of your oregon. Just connect to your computer and drag all the files to a folder on your hard drive. This could save you a lot of trouble later, in the unlikely event that something gets corrupted or accidentally deleted.
