You guys are crazzzzzzy. I once drug a mature muley myself for 2 miles up and down some nasty buttes and I thought that was tough. I can't imagine dragging an elk out that far. Don't get me wrong, I would try it in a heartbeat, but I'm sure its about 20 times more difficult than what I did.
My younger brother was lucky enough to get a ND elk license. I remember him being concerned about dealing with an elk miles from any road. Turns out after 23 days of hunting in the most remote areas he could find, he saw a herd of elk about 200 yards off the road while on his way to his nightly viewing area. He got out and stalked up on the elk. After a 70 yard shot the elk actually took off and ran towards his pickup and died only 50 yards away from his pickup. It was a 5x5 that scored 226 (not the biggest, but pretty nice for a DIY on public land considering he lost his patience and was willing to shoot a spike at that point in the hunt). He had a couple of people help drag the elk onto the road, drove down into the ditch, dropped the tailgate down and backed up to the steep ditch. He said his tailgate was level with the road and the elk just slid right in there. He always has been one heck of a lucky hunter/fisher...now that I think about it, maybe he's just better than I give him credit for.