The story begins approximately fifteen minutes after the end of The Vigilante of Pizen Bluff, where Scrooge McDuck is in his Money Bin together with Donald Duck and his grandnephews, having just finished telling them a story about his encounter with famous American Old West legends such as the Dalton Gang, Phineas T. Barnum, Buffalo Bill, Annie Oakley, and Geronimo.
Eventually, the Ducks manage to escape and get back to town, where the robber has already been arrested, thanks to Scrooge's clever advanced thinking.
Jacob Waltz, the Peralta family, and Eusebio Fransesco Chino, mentioned in the story, are all real historical characters.
The only things Rosa invented for himself are the deciphered meaning of Peralta's markings and the connection between Eusebio Fransesco Chino and the lost mine.
Donald's sharp eyesight when deciphering Peralta's markings is a reference to Rosa's earlier story, An Eye for Detail.