I know this thread is a little old, but I have some updates for y'all:
1. Frank ain't going in that hole for a million dollars. There was a book about the Chevy Corvair called "Unsafe At Any Speed". A book about the 34 foot vertical shaft and horizontal adit would be titled "Unsafe At Any Depth!" The entire tunnel is dug out of hard packed sand, rocks, and boulders. Salvador only went to the bottom of the 34 foot shaft. He didn't make it to the spiral. I also know the guy that dug the 34 foot vertical shaft, and has some VERY interesting stories about the place.
2. Marius, I hate to tell you, but all your GE Pics and psychic consultations are wrong. The "Calendar Stone" was not from the Superstitions. It was from the San Tan Mountains, which are about 35 miles Southwest of the Superstitions. The Pima Tribe know exactly where the stone is. I won't say where it currently is (NOT at the Mormon Temple at Mesa), because that is someone else's research. The confusion came because it was from Hieroglyphic Canyon in the San Tan Mountains (not the Superstitions):
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Mike