During the last decades of his life, Shaver devoted himself to "rock books"—stones that he believed had been created by the advanced ancient races and embedded with legible pictures and texts.
În ultimele decenii ale vieții sale, Shaver s-a dedicat "cărților pietre" ("rock books") - pietre pe care el le considera ca fiind create de rase avansate antice și prevăzute cu imagini și texte lizibile.