Mammoth Hot Springs, Yellowstone National Park, Wyoming, US

These are terraces seen at Mammoth Hot Springs, Yellowstone National Park, Wyoming, US. Photographed on 12th September 2012, the second day of a wonderful week's trip with great friends from England, to Yellowstone and Grand Teton National Parks.

I visited Mammoth Hot Springs and the rest of Yellowstone National Park 32 years ago, when my kids were very young. Loved Mammoth Hot Springs, so was thrilled to get the chance to see this fascinating area again.

"Mammoth Hot Springs is a large complex of hot springs on a hill of travertine in Yellowstone National Park ... It was created over thousands of years as hot water from the spring cooled and deposited calcium carbonate (over two tons flow into Mammoth each day in a solution). Although these springs lie outside the caldera boundary, their energy has been attributed to the same magmatic system that fuels other Yellowstone geothermal areas... A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption. They are sometimes confused with volcanic craters."

en.wikipedia.org/wiki/Mammoth_Hot_Springs

For a diagram of the Hot Springs layout:

en.wikipedia.org/wiki/File:MammothHotSprings.JPG

Map of Yellowstone National Park:

hfc.nps.gov/carto/PDF/YELLmap2.pdf