I don't think so?
I'll try to describe it a bit better;
If you take the trailer plug wire, and run it backwards down the length of the tongue towards the trailer (lay it on top of the tongue); it should stop some way back say- 2 feet. Take the plug end that would normally be on the truck, and screw it down to the top of the tongue where the plug wire runs to. You get to the trail/rocks, unplug it and run it back along the top of the tongue and plug it into the dummy plug.
If you're only running a 4-pin connector, there's no real need for it to be plugged in beyond the lights. We used to hook our trailer to the back of the 4wheeler to pull it down the last bit of trail to the camp, obviously you can't plug the wire into a 4 wheeler, so we came up with that to keep it out of the way and not dangling, or wrapped around the tongue. Just a suggestion, since it sounds like you'll be hauling it through some serious business.