An epic 40 foot waterfall carved through the lavaflows creating the western wall of the Yellowstone Caldera.
The Yellowstone Supervolcano is one of the most active geothermal areas on earth with more hot springs than anywhere else on the planet. The walls of the massive caldera of often hidden under snow and forest, but in places like Firehole Canyon you can see the Firehole River cut through massive lava flows.
The Falls themselves can be found along Firehole Canyon Road about 16 miles east of West Yellowstone. There are several parking areas and use trails to viewpoints over the Falls. Farther upstream there is an excellent swimming area.