The men had found adequate sustainence hunting and resolved to try for Santa Fe to buy more horses. There is no further details about the method of packing. The next few pages chronicle an amazing story of privation and endurance, capped by a classic tale of flintlock difficulties shooting a buffalo which we can all relate to. Again, we read another journal of hardships, sickness, and perserverance. Unfortunately, these entries are sparse on details of the packing arrangement.
Common sense dictates having the hands free to carry guns.
One can infer some sort of shoulder straps or tumpline, but no particular evidence of frames is present. Nor do we see ready reference to the horse packing arrangement. Presumably all these details were common knowledge at the time.