St. Louis, Missouri
July 7, 2002
Geyser Hill is in the upper geyser basin and just north of Old Faithful. This is a very easy walk from Old Faithful Inn. There are over 40 geysers on geyser hill. Two of these, Giantess and Beehive are among the largest in the world.
Old Faithful is in the Upper basin. It is one of 5 predictable geysers. It is a cone-type geyser and erupts every 35 to 120 minutes. Its eruptions last from 1 1/2 to 5 minutes and reach a height of 90 to 184 feet.
Geysers are caused when the water is constricted from moving freely underground. The pressure increases until small bubbles of steam actually push heated water out in a forceful manner.
From journal Yellowstone, a Geological Wonder