hal...i think you are giving those people more credit that they deserve....they weren't worried about future generations...the saguaro trail markers were done so THEY could relocate their workings
I have a general idea of where some of these saguaro markers are (were) thanks impart to cactusjumper's stone map solution.
It would be hard to explain any authentic map that used the same trail system.
Anyway, I agree that the saguaros, when read together, define a map, but they are as you wrote, "markers".
Markers are not maps.
Actually, here, I think that both were used to ensure success.
It would have been a long, expensive, and dangerous journey from Sonora to the Rio Saldo.
If "they" include or were the Peraltas, "they" would have had 32 years as citizens of Mexico to develop the mines of the Rio Saldo (1821-1853)... this is the Mexican period.
From 1821, to the first exploration of the Superstitions, I define as the Spanish period (Including Jesuits) 1732(?).
Adding a potential 89 years to the time mining could have happened in the range.
About 121 years of
potential time to explore, discover, and develop Las Minas Del Sombreo.
That is four, perhaps five generations.
While I am not convinced of a massacre, I do now believe that Mexicans were mining the Superstitions.