The park was created in 1941 to preserve one of the most unique ecosystems in Chile. Its particular characteristic is that it is the northernmost remnant of valdiviano rain rainforest being isolated from the rest of temperate forest by the disappearance of these product end of the last glacial period. This remnant was sustained by a particular weather phenomenon, which is the condensation of coastal fog (camanchaca) product crossing the Humboldt current with winds from the sea. This creates a particularly humid environment -already in maintaining a degree of deterioration important- forest characteristics.