Don't know if Old wants to include the stone crosses in this discussion, but for myself, they have added to my understanding of the greater history which they at the least, represent.
The Crosses, along with the Cursum Perficio drawing/map may in reality, apply to something other than the "Peralta Treasure" that Travis was looking for. However, I can't say at this time who might have made them....or when/where.....exactly
The "legends" of the LDM/Peralta mines in the Superstition Mountains are undoubtedly what influenced most folks, including Travis, in their beliefs, which is why they are commonly known as the "Peralta Stone Maps", but the Horse of Santa Fe and "SANTAFE", both found on the H/P stone hints at something far greater and more of a religious nature than a mere cache of gold left behind by Mexican miners. The more descriptive phrase "Treasure of the Church of the holy Faith" which is only found on the one stone cross as well as the CP drawing corroborates this IMO. Any reasonable proof of Travis finding Jesuit era artifacts or other SJ "treasures" would also substantiate that description.