After walking through the Lower Terrace of Mammoth Hot Springs, we continued on a drive around the Upper Terrace section. The short 2 km drive loop contains less sights than the walk around the lower section, however, there are still many interesting landmarks.
We didn’t drive far when we noticed a Yellow-Bellied Marmot perched on top of the white rock formations. We were looking at it and trying to take pictures, while causing a traffic jam on the narrow one-way road!

Next along the road we took a quick stop at the Orange Spring Mound, a large, orange-shaped dome. Orange Spring Mound has orange colouring from the heat-dwelling bacteria living in the warm water, and algae. The smooth white surface of the mound consists of calcium carbonate (travertine) deposited from the water flowing up from deep underground.

Continuing through the Upper Terrace we passed by Tangerine Spring, White Elephant’s Back Spring, and the eerie Angel Terrace. Dead trees are silouetted against the pale ground at Angel Terrace.


After leaving the terraces at Mammoth Hot Springs, we continued on around the northern area of Yellowstone National Park. We took a quick look at Undine Falls (my dad calls this Undie Falls), and then continued on to the petrified tree before heading back to our motel. The petrified tree is special in that it is still standing!

