Lava Creek Tuff is a tuff formation, in Wyoming, created when the Yellowstone Caldera erupted about 640,000 years ago.
The Lava Creek Tuff distributed in a radial pattern around the caldera and is formed of 1,000 cubic kilometers (240 cu mi) of ash in pyroclastic flows.
The tuff has been exposed by erosion at Tuff Cliff along the Gibbon River.
Lava Creek Tuff ranges in color from light-gray to pale red in some locales. Density of the tuff ranges from fine-grained to aphanitic and is densely welded. Thickness of the tuff layer ranges from 180–200 m (590–660 ft).