Heres the shot downhill with somne graphics. Red circle is the rock. Blue squiggly line is a small steady flow of water that made the area in the green circle very soft, muddy and mushy. At the same time it is also angled on a down slope on the side of the hill (red Arrow). You can see that people have put rocks and a stump in there to try to get traction. Ok for going down but going up is another story. When going up, if you kept your right tire on that mushy stuff, your left tire would have to go up the 18-24 inch vertial rock that is jutting out there. Off camber while sinking in mud while one tire does a vertical climb. Even after getting the front up, the lighter rear would have to do the same thing.
You can see from the 2nd pic, the muddy green area in relation with the trickling water and the rock wall. About 18-24 vertical inches tall.
The way they worked it out with minimal frame carnage (I heard metal hitting rock), follow up the small rock step by the right tire of the truck in the pic (or your left if you were driving) and the other upward truck tire (your right) would be scraping the right side of the rock by the muddy area and water trickle. How much to the right just depends on how wide your wheelbase and wheel offset is. The guys with the NISMO front and rear lockers made it look easy but 2 or 3 out of 6 trucks needed a static recovery strap help from the next truck above the rocks.
I got smart and backed out of that mess. Like JD said, going down is no prob with a little frame scraping but going up that is a different story. Doable but I wasn't interested in trying without Skid plates.