Jeju uprising to Jeju from Busan and deploying police companies, each 1,700 strong, from the southern provinces of the mainland. The guerrillas retreated to their bases in the forests and caves around Hallasan, an extinct volcano and the highest mountain in South Korea. On April 29, the Korean, non-military, governor of Jeju province abandoned his post, defected, and joined the guerrillas. This caused many police officers, disillusioned by the atrocities they were ordered to commit against their own, to do the same. In response, U.S. military provincial governor William F. Dean ordered a purge of SKLP sympathizers from the ranks of the
Hallasan because of the peak of the mountain. The crater of the mountain looks like a big pond. According to a legend, a white deer used to drink the water here. Hallasan is a massive shield volcano which forms the bulk of Jeju Island and is often taken as representing the island itself. There is a local saying that "Jeju Island is Hallasan, and Hallasan is Jeju." The mountain can indeed be seen from all places on the island, but its peak is often covered in clouds. The mountain has been designated Korea's Natural Monument no. 182. The soil of Hallasan