Does anyone know of a RTS/Strategy Computer game of the type of Resident Evil, or I Am Legend?

Im looking for a new computer game to play, as some sort of last human colony on earth. Vs Zombies or somthing of that sort. Any game that can relate to the movies mentioned above. Build a base/colony, gather resources, survive... Anything of that type. Im a huge fan of the RTS Genre, and im to all the big titles. I just cant seem to find something that relates to RTS Zombies, or Nuclular holocaust survival fending off mutants, or other human colonies looking for resources. Any mention of anything close will do. Thanks in advance.