Yellowstone National Park
Yellowstone National Park has one of the world's largest petrified forests, trees which were long ago buried by ash and soil and transformed from wood to mineral materials. This ash and other volcanic debris are believed to have come from the park area itself as the central part of Yellowstone is the massive caldera of a supervolcano. The park contains 290 waterfalls of at least , the highest being the Lower Falls of the Yellowstone River at .
Annie Falls
Annie Falls, is the tallest of three waterfalls so named, located along Annie Creek in the Crater Lake National Park at the south end of Rim Village Historic District, in Klamath County, in the U.S. state of Oregon. It is located in a steep canyon area surrounded by walls of petrified volcanic ash as a consequence of the Mount Mazama eruption. The location of Annie Creek Falls deep in the Annie Creek canyon makes it very difficult to reach the waterfall. Partial views of the cascade can be seen from a picnic area off the Volcanic Legacy Scenic Byway south of Crater Peak. Access to Annie Creek is available at the USFS snow park, both the creek and the waterfall possess a high water flow.