On a spring vacation several years ago, we ventured into Yellowstone National Park for the first time. It was like stepping back into another century, or another world, seeing for ourselves these geysers and springs that had captivated the country for more than 100 years. As we were touring the area early in the year, the only entrance open in the beginning of our trip was the Mammoth Hot Springs entrance on the Northern end of the park. The entrance nearest Old Faithful would not open for several days.
As it was our first visit to any part of the park, we took advantage of this time to explore the Mammoth Hot Springs area and learn a great deal about the various thermal features in the park. While Yellowstone boasts an estimated 10,000 thermal features, they are broken down into four main types: geysers, hot springs, fumaroles and mudpots. All are related and created due to the large amount of volcanic activity occurring underneath the surface of the park and each will be explored in this series of posts. Of course, the fact that these features are created by volcanic activity also means a volcanic eruption could occur at any time in the park, but other than geysers shooting off their mouths, that has not occurred in a very long time. However, that unpredictability is part of the mystery and magic of Yellowstone.
So, on our first visit to America’s very first national park, we were all about Hot springs. Different from geysers which release hot steam and water in a rather explosive fashion, these less showy thermal siblings let off enough heat by boiling or surface evaporation to avoid the kind of steam explosions common to geysers. Some hot springs take the form of quiet pools while others are flowing and a bit more active.
The waters at Mammoth Hot Springs are charged with carbon dioxide while underground, creating a mild carbonic acid that dissolves underground limestone rocks and carries the mixture to the surface of the earth. Once at the surface, the gas escapes; however, without the carbon dioxide, the water is less able to carry the dissolved limestone which escapes by virtue of precipitation, creating the beautiful travertine terraces you see in these pictures. They are quite lovely to behold, and in some areas, volcanic activity can turn a hot spring into a geyser.
Learning about these unique features fascinated our entire family and, after spending the afternoon snapping photos of the Mammoth Hot Springs and beautiful travertine terraces, we made plans to return several days later when roads to other areas of the park would be open. We wanted to see more. Even though this was, in effect, a science lesson while they were on vacation, the kids couldn’t wait to return!
For more information about things to do in Wyoming, read more about Wyoming camping.