The oldest narrative material about Korean deities comes from a Buddhist monk's compilation of the thirteenth century, the Samguk Yusa, which gathered legends, foundation myths and miracle accounts left out of the official dynastic history. The story of Hwanung descending to found a kingdom, and of the bear who became a woman, reaches modern readers through it. It was written centuries after the events it reports and by an author with commitments of his own.
For most of the intervening period, the tradition was documented by people who disapproved of it. The Confucian state of the Joseon dynasty treated folk practice as disorder and its records concern suppression. Christian missionaries added another hostile archive. Japanese colonial authorities conducted extensive ethnographic surveys of Korean folk religion for administrative purposes, and that material is detailed, is still used, and was gathered as part of governing an occupied country.
The tradition itself transmits orally and in performance. The gut is not scripted, its chants are learned in apprenticeship, and it varies substantially by region.
Since the later twentieth century, Korean folklore scholarship has taken the subject seriously on its own terms, and several ritual forms have been designated as intangible cultural heritage, which preserves them and also fixes and formalises performances that were previously fluid.