This is similar to my previous Google Maps. The useful addition here in relation to the site CUP file is that I have used Google Earth to scout out a bunch of landing options. Most of this work was from two years ago, though I glanced over the pictures and they still look reasonable.
Landing areas that are nearly certainly good are marked in yellow. Orange are un-scouted (at least recently) fields. Red areas are emergency landing options. Bear in mind that this map was largely prepped for Aero Club Albatross members, flying a 1-26. Higher performance ships should be wary of going anywhere other than the yellow options unless the pilots scout out the fields themselves.
To change layers, click the top left box on the edge of the map. You can also change the base map from satellite view to terrain view.
You can download the fields layer as a KML file and convert it into a CUP file using this link. This would mark the fields as waypoints in your device. However, do so at your own risk! Research the fields if you do this as some are marginal.