Catherine Parker More than its star attraction (Old Faithful), the Upper Geyser Basin boasts not only the largest concentration of geysers in the park, but also in the entire world (Yellowstone is ...

Yellowstone National Park is a place where steam rises from the earth and geysers erupt like clockwork. Parameters were ...

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 Lone Geyser Trail is in Upper Geyser Basin, about 3.5 miles south of the Old Faithful overpass on Highway 191. There are vault toilets available, though no other amenities, so hikers will need ...