In the 14th century Yeshe Gyaltsen, a Bonpo monk from Yaru bensa kha Monastery and originally from Sog de in Nagchu kha, asked his main master, mTha’ bral bSod nams rgyal mtshan, about his future. His master told him that he was to spread the doctrine in a land called Yang lung in northern Amdo. Following his master’s instructions, he left for Amdo in search of the place. The master gave Yeshe Gyaltsen a reliquary for keeping sacred items exhorting him repeatedly not to open it before reaching his destination, but Yeshe Gyaltsen’s treasurer, overcome by curiosity, opened the reliquary on the way and a pigeon escaped from it. The bird was in fact Magpon, a guardian of the Bon religion, which is why, it is believed, Magpon is propitiated by the Bonpos living in Kokonor to this day. When they reached the shores of Kokonor lake they learnt that Yang lung corresponded to the three valleys of Trika, and thus proceeded in that direction. When they reached Tongche valley, the mule carrying their belongings dropped to the ground. Yeshes Gyaltsen took this as an auspicious sign. He decided that they would settle there and drove his phurpa dagger into the ground. The temple he built on the spot became Khyungmo lhakhang which survived until the middle of the 20th century. (The temple was built in the old architectural style with the three Buddhas of the Three Ages at the entrance flanked by eight sempa’ on either side). The temple is the earliest of its kind in Amdo; indeed, since Yeshes Gyaltsen arrived there from central Tibet, the temple was built in the original, central Tibetan style. Yeshes Gyaltsen became renowned as Tongche ton pa, also called Sog De Tonpa. the “monk from Sog de” (in Amdo). He also built a monastery at the site of the present Pon Tsang lhakhang, but since its location in the center of the village was inconvenient, it was moved to the present site of Khyungmo Monastery a few generations after its foundation. It was during this period that the first temples in Tongche valley were founded.