sentences:  The southern and eastern slopes drain to Pillanleufú River which flows south along the Liquiñe-Ofqui Fault to Maihue Lake.The two volcanoes have had several historical names such as Valdivia, used by Juan Ignacio Molina in 1795, and Panguipulli and Lajara, which Pedro Amadeo Pissis identified in 1875 as Choshuenco and Mocho respectively because only Choshuenco is visible from Panguipulli Lake.Other historical spellings and names for the volcanoes include Choshuenco-Pillán, Rauco, Penguipulli, Reñihue and Riñihue.