Sorry, Edgar, for the delay in responding. Personally, I doubt any Hearst conspiracy in Bierce's disappearance. Hearst was preoccupied with his fantasy of being elected president and Bierce was a mere annoying fly buzzing at the window. A National Geographic expedition to find Bierce's remains somewhere in arid Mexico? Would be pure folly -- and more expensive than sending a landing party to Mars. I like your idea, however. Might be a great short story for the Ambrose Bierce Site -- which you are designated to write!
I also apologize for the annoying and intrusive ads on this message board. It's the price for a free board.