The folklore of Gunung Gamping in Yogyakarta, Indonesia describes us the story of two servants in the Mataram Kingdom of Yogyakarta under the leadership of Sri Sultan Hamengku Buwono 1. The story is also the basis for an annual tradition called Saparan Bekakak in the month of Sapar in the Javanese calendar. This oral literature describes to the relationship between past natural events with the mystical and sacred things. The avalanche of Mount Gamping is the basis for the creation of this folklore. Starting from that, this folklore emerged as a propaganda media of the royal government policy at that time. The Mataram Kingdom of Yogyakarta at that time wanted the swift mining of Mount Gamping as the source of raw material for the construction of the palace. However, the other function behind the emergence of this story that has been passed down between generations has not been realized.This research examines the relationship of Gunung Gamping folklore with historical records and past geological events in the realm of geomythology to find new functions of Gunung Gamping folklore. The perspective used is the theory of oral literature function. Data were collected through field observations, interviews, literature studies, and documentation.The findings show that Gunung Gamping folklore contains four functions in general, namely (1) the function of the projection system; (2) cultural validation; (3) child education; and (4) social norms. In addition, there is one new function found in this study, namely the function of legitimizing past political policies. The finding of this new function is an advantage and novelty of this research and can be a reference for folklore studies in the future.