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
Newberry Volcano Mount McLoughlin, and the Three Sisters volcanoes. Newberry Volcano Newberry Volcano (also known as Newberry Caldera) is a large active shield-shaped stratovolcano located east of the major crest of the Cascade Range and about south of Bend, Oregon, within the Newberry National Volcanic Monument. Its highest point is Paulina Peak. The largest volcano in the Cascade Volcanic Arc, it has roughly the same area as the state of Rhode Island at when its lava flows are taken into account. From its northernmost to southernmost point, the volcano is in length, with a width of and a total volume of approximately