If you can find an appropriate image of the map you are looking for (satellite or otherwise), the Civ3 editor I wrote has functionality to create maps of arbitrary sizes (of less than 65,536 total tiles) from BMP files. You'd have to do some work yourself, like placing rivers, resources, mountains, and various aspects of fine-tuning, as it can handle things like coastline well, generally differentiate arid/temperate/arctic/and forested areas, but has trouble with things like elevation and distinguishing jungles from other types of dense forests. Still, for getting the first draft of the terrain re-created, it's a lot more accurate than eyeballing it, and a lot quicker than charting it out on paper.