So how do you get OSM img files to show up in your Monterra?

I put some into my SD card Garmin folder and they don’t show up in the map under “Setup Map/Map Information”

More complete information on the services is here

http://cumulus.cr.usgs.gov/services.php

The link I gave here is for HRO (hi res) images (less than a meter per pixel) from 2005. They have 2009 NAIP imagery for Oregon but it's 1 meter pixels. So it depends on what you are trying to do -- capture details for things like bike paths or get more current data possibly for new streets. I was going for details.