Can't load Washington Top to Garmin Oregon 450t

[MPH]

Just bought Oregon 450t and 8 gig SD chip with the hope of being able to download 24k topos from websites, etc.  I tried to follow the instructions on GPSfiledepot, but to no success.  I can see all the map files (I assume these are individual 24k maps) on the micro SD chip when it is hooked up to the PC and that they have the extension .img but when I go to Setup>Map>Map Information Select Map  I cannot see them in order to select them for use.  Also of note, if I try to open them on my PC in MapSource it says Washington Topo/22C29297.img is not a valid MapSource file and cannot be opened.  Any ideas what I am doing wrong?

[jbensman]

You need to  clearly describe what you did

[MPH]

I started by putting an 8 GB micro SD card into my new Garmin 450t.  Then I went to GPS File Depot and downloaded: Garmin Training Center, Garmin MapSource, and Washington 24K Topo Map.  Washington 24K Topo Map created file folder on my PC where it placed a large number of .img files which I could not open directly, nor could I open while in Map Source.  Just guessing what to do next I copied and pasted the .img files directly to the SD card and tried to open them using the GPS device with the command series Setup>Map>Select Map but could not see any sign of the files.  I could see on my PC that they did copy to the the card they just aren't visible to select from.  When I tried to open the .img files in Map Source I get the error message that Washington Top/22029297.img is not a valid map source file. 

I would be happy to erase all these files and start again if there is a better way.

Thanks for any ideas you might have.

[Seldom]

Follow this tutorial:
http://www.gpsfiledepot.com/tutorials/how-to-open-maps-in-mapsource/
Washington Top should appear as one option in the dropdown window shown as item 2.