This geyser has a long standing rhythm of eruptions that can be timed and viewed on schedule.
The description states:
THE CELEBRATED OLD FAITHFUL GEYSER NAMED FOR ITS REGULARITY OF ERUPTION INTERVALS IN 1870 BY GENERAL HENRY D. WASHBURN
YELLOWSTONE NATIONAL PARK
— The intervals have become more regular and predictable over the decades, and now occur at two very distinct intervals based on the length of the previous eruption. This card likely dates from the 1950s.