Bishop Tuff

Bishop Tuff is a volcanic formation made of welded ash and pumice that spreads across a plateau in Inyo and Mono Counties, California. Erosion has carved distinctive stone columns and wave-like patterns across the surface.

This formation was created by a volcanic eruption roughly 764,000 years ago that lasted six days and formed the Long Valley Caldera. The event was one of the largest eruptions to occur in the Sierra Nevada region.

Geologists and researchers analyze the tuff layers extensively to understand volcanic processes and develop regional eruption prediction models.

You can reach the formation via roads near Crowley Lake and Bishop, with multiple viewpoints allowing you to see the structure from different angles. The warmer months offer the best conditions for exploring and observing the layered deposits.

The Owens River has cut deep gorges through the volcanic tableland, revealing different mineral layers within the rock. This natural erosion exposes the composition of the stone in a way that rewards closer observation.

Location: Inyo County

Location: Mono County

Made from material: tuff

GPS coordinates: 37.50000,-118.50000

Latest update: December 10, 2025 16:03