Continuing our tour through the Mammoth Hot Springs. It was a surprise for me to learn that the hot spring colors are produced by living creatures! Thermophiles are microorganisms that thrive in heat. Those living in the hottest water are colorless or yellow.

The people of the Shoshone and Bannock tribes came to Mammoth to collect minerals to make white paint.

Cooler waters contain orange, brown and green thermophiles. Sunlight also influences which colors you may see.

When hot springs rise up through limestone, they dissolve calcium carbonate. The resulting calcite is then deposited, creating travertine terraces.

These are the Palette Spring terraces coming down from the thermal pool above them.

.To my surprise, there were quite a few birds hopping about, including a chipping sparrow (Spizella passerina) and very colorful yellow-rumped warblers (Setophaga coronata).

Mountain bluebirds (Sialia currucoides) were a delight to see.

The trail through the Hot Springs complex winds around for more than 2 miles. As I was walking along one area at the bottom of a steep hill, some fellow tourists approaching me said there was a coyote going up the hill further on. I hurried on and caught sight of him as he neared the top.

You reach the Upper Terraces by climbing steep stairs.

There were more trees along the upper pathway with fumaroles (venting steam) nearby.

I did catch sight of some eagles soaring over the large flat springs expanse, but I was happy to go back down to the lower terraces. (Unfortunately, sliding my gloved hand down a wooden railing on the descent gave me a splinter in my palm that I did not manage to get out completely. I had a very sore hand for quite some time: unwanted souvenir!)

I lost track of exactly which places had which names — looking them up on the Internet is not always helpful because the Mammoth features have changed considerably over time. When a hot spring remains dormant for a long time, it will eventually be covered by soil and again create an environment for trees and flowers. To complicate matters, the names of sites have changed over time.

The name Cleopatra Spring has been given to at least three different sites over the years. The original Cleopatra Spring eventually came to be called Minerva Spring. This was, I believe, the current Cleopatra Terrace.

When trees are flooded by hot water, they absorb calcium carbonate. This hardens their veins so they cannot absorb “normal” water and nutrients and they harden into what look like petrified trees which may stand for decades.

The hot springs were an early commercialized attraction for those seeking relief from ailments in the mineral waters.

Today, to preserve these unique and fragile features, soaking in the hot springs is prohibited.

Next stop in Yellowstone: The adorable red dogs!