Weren't there silver mines nearby?
Doesnt like everyone in the childhood go on treasure hunts?
All of these accusations from what I gather are pretty weak.
Archaeologists and scavengers have found many silver articles in the mounds of the Ohio valley and adjacent areas, as well as amidst deep piles of old bones apparently left from some genocidal wars of long long ago. Lots of helmets, shields, rocks carved for a handhold useful in managing large boulders intended to crush skulls, lots and lots of arrowheads, spear points and such. Copper was much used as well, and there were some mines in the area. Most of the copper and silver seems to have come from a very abundant deposit in a peninsula of the Great Lakes. . . . I'm sure locals discovering these things started making up stories about the mysterious ancients. . . . but aside from some dusty academic works written in the 1800s in the libraries of New York, there's no great popular account of it all. . . .