It's a well-used tactic, dog - tried and true for a hundred years, more or less. There's always a map (or a document) surfacing every generation or two that brings attention back to a "treasure vicinity". Normally, it's a mysterious "Mexican with a map" who shows up somewhere looking for "signs on the map" and dupes a local into helping him, but never actually shows the map. Typically, this breathes life into an old rumor, begins a fresh new frenzy, and the searching begins anew. Has worked many times in many places.
In np's case, I suspect he's been duped by the Noss family with his maps. Of course, I could be wrong, but the whole thing has an obvious Noss-scam stain on it. I believe there is something interesting is in the Caballos, yes, but IMO we've been sandbagged since the 1930s.