Hike through Pinnacles Valley at Crater Lake NP

These 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.

This trail makes for an easy walk along the rim of Pinnacle Valley, and ends at the Crater Lake National Park boundary.