Yellowstone National Park, Wyoming

B. Hippo visits Old Faithful Geyser in the Lower Geyser Basin at Yellowstone National Park

Old Faithful, shown here, is surrounded by many other geysers and fumaroles, though none are quite as predictable as this one.

Among the geysers, the air smells humid and sulfury. B. Hippo learned about the different geothermal features, of which about half of the worlds supply are here in Yellowstone, at the ranger station before heading out.