Bottom photo is one long postcard, I took the upper right.
Journaling reads: Old Faithful is a geyser in Wyoming in Yellowstone National Park. Old Faithful was named in 1870 during the Washburn-Langford-Doane Expedition. It is the most predictable geographical feature on Earth erupting almost every 91 minutes.
In the early days of the park, Old Faithful was often used as a laundry. Garments which were placed in the crater were ejected thoroughly washed when the eruption took place. In 1882 General Sheridan's men found that linen and cotton fabrics were uninjured by the action of the water but woolen clothes were torn to shreds.
Eruptions can shoot 3,700 to 8,400 US gallons of boiling water to a height of 106 to 185 feet lasting from 1.5 to 5 minutes. Intervals between eruptions can range from 45 to 125 minutes, averaging 66.5 minutes in 1939 and slowly increasing to an average of 90 minutes apart today.
The longer intervals between eruptions may be the result of earthquakes affecting subterranean water levels. These disruptions have made the earlier mathematical relationship inaccurate, but have in fact made Old Faithful more predictable. Old Faithful will erupt 65 minutes after an eruption lasting less than 2.5 minutes or 91 minutes after an eruption lasting more than 2.5 minutes.
Whenever Old Faithful erupts the time of the next eruption can be predicted with only a 10 minute margin of error. Eruptions can not be predicted any further out than the one after the current eruption since the predictions are based on the time length of the current eruption.