I have moved logs out of some complicated terrain using a pulley high up in a tree to act as a fairlead, and a long logging rope. Attach rope to log with a chain, run rope up through fairlead and over to your tractor/truck/car/etc (which would be on manageable terrain). The logging rope will be expensive though -- I think I paid about $250 for 200' of 5/8 rope about 5 years ago (which is now in two shorter pieces because I was lazy, didn't reel it in after pulling a log out, and accidentally tagged it with a chainsaw while bucking).