Geysers Seen from the Webcam
Old Faithful is in the Upper geyser Basin, one of three large geyser basins along the Firehole River. The majority of the world's active geysers are found here. Many of them have been caught in euption by the Old Faithful Webcam.

Predicting Old Faithful
There is a direct relationship between the duration of Old Faithful’s eruption and the length of time before it erupts again. During a short eruption, less water and heat are used, so both are restored in a shorter time. During longer eruptions, the opposite happens—more water and heat are spent, which means more time is needed for these ingredients to rebuild.

(Next predicted eruptions of Old Faithful are posted on the webcam by visitor center staff when the center is open. More... )

It is not possible to predict more than one eruption in advance with any accuracy. The time of the next eruption is predicted by using the duration of the current eruption. The eruption’s length is timed from when the water comes out and stays out of the geyser’s cone for at least five seconds until the last appearance of water at the eruption’s end. The longer the eruption lasts, the longer it will be until the next eruption.