The largest concentration of geysers in the world is in the Old Faithful area, also known as the Upper Geyser Basin.

Old Faithful erupts more frequently than any of the other big geysers, although it is not the largest or most regular geyser in the park. Its average interval between eruptions is about 91 minutes, varying from 65 - 92 minutes. An eruption lasts 1 1/2 to 5 minutes, expels 3,700 - 8,400 gallons (14,000 - 32,000 liters) of boiling water, and reaches heights of 106 - 184 feet (30 - 55m).

This is the Old Faithful geyser. Unlike other geysers, this one is very predictable.

My parents with Anjana in our cabin next to the Old Faithful Snow lodge.

Anjana in the most active geyser basin of the world at Old Faithful.

The Old Faithful Snow lodge in the background.

As we were walking past the Sawmill Geyser, it suddenly started to errupt.

Sawmill Glacier going active.

As we were leaving the parking lot, the Beehive geyser started to erupt.

A rare scene of two geysers erupting at the same time. The Beehive geyser is to the left and the Old faithful geyser is to the right.

Old Faithful Area / Upper Geyer Basin

Lower Geyser Basin between Old Faithful and Madison

I would like to acknowledge the National Park Service as the source of the maps presented in the web site. We are very thankful to the National Park service and its rangers for doing such a great job in  preserving the treasure chests of nature and helping us around in our quest to get familiar and enjoy these wonders.