Lightning strikes above the Fan and Mortar geysers in Yellowstone's Upper Geyser Basin. Geysers are formed when underground water meets superheated rock and blasts back out through a narrow hole.

The Midway Geyser Basin's Grand Prismatic Spring ... National Park Service's Grand Prismatic Spring page. Lower Loop Van Tour from West Yellowstone: Grand Prismatic and Old Faithful (295 reviews) ...

To get a good sense of Yellowstone’s geothermal features, Hunter likes “everybody to see the Lower Geyser Basin, where the Fountain Paint Pot is. If you go to those two, you don’t have to go ...