It regularly blows its top, 6 letters
Natural steam source, 6 letters
Old Faithful, famously, 6 letters
Old Faithful, for example, 6 letters
Old Faithful, for one, 6 letters
Word from the Icelandic for gush, 6 letters
Yellowstone attraction, 6 letters
Yellowstone feature, 6 letters
Yellowstone Park attraction, 6 letters
Yellowstone Park sight, 6 letters
Yellowstone spouter, 6 letters
Yellowstone's Giantess, for one, 6 letters
Yellowstone's Steamboat, for one, 6 letters
A spring that discharges hot water and steam, 6 letters
Musical about Old Faithful?, 14 letters
24 undeveloped photos of Old Faithful?, 10 letters
Jet stream generators?, 7 letters
Old Faithful and others, 7 letters
Some thermophilic habitats, 7 letters
Surface phenomena affected by magma, 7 letters
They blow off steam, 7 letters
Where some jets originate, 7 letters