One important way that Mammoth Hot Springs differs from the other geothermal areas in Yellowstone is the composition of the deposits there. Most of Yellowstone's thermal features create deposits of geyserite, a rather hard silicate material that over time allows the formation of the solid cones and underground structures that permit geysers to form. In contrast, Mammoth's springs deposit a material called travertine, a form of calcium carbonate. This is a much softer material, and will not maintain its structure under pressure, which is one reason why there are no geysers at Mammoth.

As the water containing dissolved travertine percolates up and then down over existing structures, fascinating patterns of "stairstep"-like terraces are created, both large and small. This view is about 10 to 15 feet across, showing the interesting shapes and varying hues of the travertine.

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