Leaving aside the option to take a side-by-side/ATV/snowmobile (with skid or trailer if needed) to solve the problem with horsepower, or the option of biologica

Leaving aside the option to take a side-by-side/ATV/snowmobile (with skid or trailer if needed) to solve the problem with horsepower, or the option of biological horses instead of petroleum horses: 1. You first field dress it - cut from sternum to tail and pull the entrails, leaving them in a pile in the woods for scavengers. That takes your elk from 700 lbs (you hope) to ~450 lbs. 2. Quarter it and hang the 4 ~100lbs quarters high in a tree safe from bears and wolves (but not cougars) and carry them out one at a time using a backpack with a frame and hip belt. Be sure to carry the prime cuts (backstraps) out with the first load. Watch for predators on the return trips. 3. It's becoming more common, too, to fully butcher the animal in the field, removing the bones, which reduces the load to haul down to about 200 lbs. The skin, ivory, and head (if you want those) add some weight. A Jet Sled in 2" of snow makes it surprisingly easy to haul an awful lot of elk and gear. As long as you're going across flat ground or downhill, that is - uphill is no fun at all. A whitetail here in Michigan is much easier, even a big one is only about 100 lbs after field dressing. You just lay it on a drag/tarp or in a sled (or, if you don't care about the skin staying pristine and aren't going over super rocky terrain, just tie a rope to the antlers and front legs) and drag it out.