Save yourself a lot or grief of the cheap winch and just buy about 80' of 1/4" cable at hardware store, get yourself a snatch block, put hooks on cable and use it to go down into the ravine, use tractor to pull log up to top of hill then back tractor up to it and haul out with tractor. You can put the snatch block up as high as you want in a tree.
You are probably not going to get enough height to make winch practical... Probably need a skidding cone (I know has other names) to keep cut ends of logs from digging in....
THis is my issue, can't get close to tree, and can't get tractor in because creek is about 3 feet from where picture is taken...
Dale
DL not to hijack the thread but, Micro-blaster or Sierra Blaster will solve your access problem.