The Pinnacles – Prominent Geological Features of Crater Lake National Park
#22 on the map
These towering needle-like formations of rock, called fossil fumaroles, projecting from the Sand Creek Canyon floor, were formed under sheets of volcanic pumice that preceded Mazama’s collapse.As the surface of the hot pumice cooled over the years, steam and gases were released by the hot rocks underneath through vents and tubes that were welded into cement hardness by their passage. These ancient vents now stand alone due to the erosion of the surrounding softer materials.
Crater Lake National Park
Prominent Geological Features Map
Note: the numbers associated with each feature name above correspond to their place on the Custom Google Map