At one time you could download the file from Flying-J.com as well
MAP OVERLAYS
Takes you to a list of POI files for most all Mapping software.. Flying-J is one of the files
They also have Wal-mart, Moose/Elk/Etc, Membership campgrounds (Assorted), KOA, State parks, .. Well a great big bunch of them. Rest areas, LOW CLEARANCE, and more.