Yellowstone sits on a constant surging magma below the earth’s crust. Besides the animals, the geysers, pools and vents are a major attraction.
The number one attraction of course is Old Faithful. It was the first geyser to get a name as it is the only predictable geyser in the park.
Over the years, the length of the interval has increased, which 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. With a margin of error of 10 minutes, 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. The reliability of Old Faithful can be attributed to the fact that it is not connected to any other thermal features of the Upper Geyser Basin.
Eruptions can shoot 3,700 to 8,400 US gallons (14,000 to 32,000 l) of boiling water to a height of 106 to 185 feet (32 to 56 m) lasting from 1.5 to 5 minutes. The average height of an eruption is 145 feet (44 m).[7] The highest recorded eruption was 185 feet (56 m) high.
There are other geysers, vents and pools throughout the park that are amazing. Here’s just a few recapped in this video.