This paper focuses on the origins of the significance of Mount Shasta for the Theosophist movements in America. It first presents the major text of the Atlantis canon, A Dweller on Two Planets, or the Dividing of the Way, by Phylos the Thibetan, alias Frederick S. Oliver, and in particular the second part "Seven Shasta Scenes " which narrates how a wise man led the narrator into the wonderful depths of the Mount to introduce him to a fraternity of higher spirits, the Lothins. Then, we look at a famous book Unveiled Mysteries, by Godfre Ray King, alias Guy Ballard, the founder of the I AM cult, who obviously got his inspiration from the first Shasta novel. Ballard replaces the Lothin fraternity with the Great White Brotherhood, a gathering o...