I would agree with what others have posted. Either a log arch or a trailer. I went the route of the trailer, but since they logged over 1100 large mature trees from the woods that I cut in last winter, I haven't had a need to get down into to the ravines with my ATV to try the trailer out. Words of caution on the trailer. Be aware of how much you have on it, and how easy it is to tip over because it can take the ATV and you with it when it goes.
The reason that I chose a trailer instead of building a log arch was A - Cost, and B - Usefullness. I bought the trailer used and made a few mods to it. I have about $150 wrapped up in it. It just is big enough to haul my ATV on, which makes it very functional for me as I hate running the ATV up a set of ramps into the bed of my '93 F250. Get a little snow or even some rain and the ATV doesn't always like to stay on the ramps.
On the down side, it has a 4' wide deck, and the 14" wheels stick out another 8 or 9" on each side, so its a lot wider than my ATV. It only has a 1K axle (or at least that's all I'll put on it) so it's limited to how much it can acutally haul by the axle, not the deck. Also, it's easy to run the wheels into stuff when I'm pulling it through the woods trying to go around trees. At that point it becomes a real pain to get everything straightened back out and moving again. What ever tree I hit is now stuck between the ATV and the trailer with little or no room left for me to turn and get things clear. All in all the trailer works well so long as there's adequate room to get it in and out, and so long as the terrain isn't super rough or too much of an incline. You can also go with one of the smaller trailers made to pull behind a lawn tractor, but you're going to need to take a lot of trips to fill up a truck bed with one of those.
I really wanted a log arch, and still do, but looking at them I can tell that I'm goign to have over $200 in one plus a lot of time. I'd LOVE to build one just for fun, but I just don't have the time, and don't have $200 to put into materials for somethign that's only able to be used for cutting firewood. If I were cutting on my own land, then I would certainly build one and just haul the logs up to the barn lot for storage until I was ready to cut them.
I also looked into the log cones/sleds, and those looked like they had some promise. You'll still have dirt in the bark which is going to be hard on your chains, but the cone/sled keeps the front of the log from digging in making it easier to drag. I've heard of guys using the hood off an old car, or modifying a plastic 55 gal drum do do this as well. I opted against it because I still had to drag the logs, and I still had to cut dirt packed wood.