<p><br>
Vapor rises from Old Faithful, one of <a href="http://travel.nationalgeographic.com/travel/national-parks/yellowstone-national-park/">Yellowstone</a>'s most popular attractions. Not the largest or the most regular of the park's geysers, Old Faithful erupts more frequently, with each blast expelling between 3,700 to 8,400 gallons (14,000 to 32,000 liters) of boiling water.</p>
Old Faithful
Vapor rises from Old Faithful, one of Yellowstone's most popular attractions. Not the largest or the most regular of the park's geysers, Old Faithful erupts more frequently, with each blast expelling between 3,700 to 8,400 gallons (14,000 to 32,000 liters) of boiling water.
Yellowstone National Park Photos
Yellowstone National Park photos and pictures of culture, history, and travel from National Geographic.