I have taken somewhere upward of three dozen elk and have not carried a bone since I was a rookie. Most of my hunting was out of spike camps that were backpacked a few miles deep . I debone the elk and cut into chunks that will fit into one gallon zip lock bags. An external frame pack with a large bag (think it was called a "moose bag") gets filled with enough zip locks and the walking starts. The number of trips varies with terrain, animal size, knees, etc., but it has always worked for me. The bags are labeled to make it easier to figure out what was in them when it came time to butcher.