This mod replaces what you see from both city view and regional view when you look at the edge of a map.  By default, it's an ugly gray color ... this mod replaces it with more natural looking soil-colored textures.  These are NOT my textures.  I simply extracted them from the SimMars terrain mods file and put them in their own DAT file.  It does not require SimMars to work. In order to see the changes from region view, unfortunately, you will need to load
each city and save it.  This is because the region view is not dynamically generated:
it is merely a compilation of PNG images saved in each city file. To install, simply drop the contained DAT file in your Program Files plugins folder.