There are two reasons people visit Yellowstone. One is to see the bears, and the other to watch Old Faithful. What they discover is that the bison are more fun to watch then searching for bears, and Old Faithful is only one of hundreds of geothermal features in the park. In fact, more then half of all geothermal features in the world are located in Yellowstone.
What is the difference between geysers and hot springs?
People are often surprised by the amount the diversity in the features. There are trickles and eruptions, and the colors? They will set rainbows aside.
Both the geysers and hot springs are fed from underground runoff. When the water warms beneath the surface from the magma, changes take place. It’s behavior is relative to temperature and what is beneath the surface. A geyser erupts when it bypasses an obstruction in it’s path, and a hot spring seeps, or bubbles at the surface.

Why are they different colors?
The colors come from a heat loving microbes that thrive in specific temperatures. Interestingly enough, while blue mimics the sky and might be thought of as a cooler temperature, it is the hottest of hot springs. The cooler change in temperature means the adaptation of other microorganisms which create the change in color.

Why does Mammoth Hot Springs look like ice?
Mammoth was formed like the other hot springs, and this time large quantities of limestone interact with the springs creating terraces of calcified limestone. To me, Mammoth resembles the top of an icy mountain, but to others the inside of a cave is a better representation.

What time do we turn them on?
To answer this I usually just smile, but it is fun to tell them about the hot springs we call Tomato Soup in the backcountry.

Always humbled by this beautiful place I also call home… Donna
Inspired by the WordPress Weekly Photo Challenge:
