Hi Stephan; Thank You for your help… I selected and loaded the files from; http://garmin.openstreetmap.nl/. My first selection included the entire State of California, but only the top half showed up. I tried the same selection from So. California first., and only this half showed up…? (I would obviously like to choose the entire US map.)… After downloading these two files to my Garmin Oregon 550, only one could be read at a time, requiring Two downloads to Two Micro SD cards… Can two files be combined? Is there a bug, where only a very limited geographical area can be selected? Thank You again for your help… BTW; the So. Cal. map works perfectly… TY mdg