Colour image: I visited Google Maps, hit f11 for fullscreen, took 4 screen grabs of my area(with MWSnap, free -
http://www.mirekw.com/winfreeware/mwsnap.html) and patched them together to make a 2048px image map. I also clone-brushed out the visible Google tags and such.
Displacement image: I then duplicated the above, desaturated, masked out the river then inverted the colours. I didn't want a displaced river, obviously.
Probably the simplest TG2 setup I've used for years, all the work was done before opening Terragen. All I needed that for was to pop in some balloons, some gentle fractal hills, add clouds and, of course, to render.
