If you want to saw on elk, get a Wyoming Saw. This works very well. If you are not mounting the head, it is nice to cut the skull cap off and leave the head sitting, rather than packing that out on your back. Likewise with the leg quarters. If you are packing that out on your own back, it is nice to be able to saw off the hooves and most of the hocks too that don't have much serviceable meat (ligaments mostly in there) and leave them in the field rather than packing them out on your back. If you've got horses or mules or llamas, of course, this surplus weight is less of an issue. I agree that rather than cutting up the pelvis just work your knife around the meat and cut loose the ball of the femur from the socket of the pelvis to remove the rear legs. The shoulder just comes off when you cut away the muscle.